Physics Unit8: Rotational Motion - https://webassign.org

1#

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Angular displacement ttm.2:mo rzb (o5xrv/ is usually express in units of

A. meters.

B. radians.

C. revolutions.

D. arcs.

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2#

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Angular velocity is expressed in jqycb7+b03zosu 5jsk;k v*)3pk 0tznunits of

A. meters per second.

B. radians per second.

C. omegas per second.

D. arcs per second.

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3#

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Angular acceleration is expressed in unitsvg0amr/exx8) xbm. eertz+sej3 +bo 0-;er)f of

A. meters per second squared.

B. radians per second squared.

C. alphas per second squared.

D. arcs per second squared.

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4#

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A boy and a girl are riding on a merry-go-round which is turnlb kze4 0;xchehj). +tf 6a)yzing at a constant rate. The boy is near the outer edge, and the girl is close)f4lt .e0hy+; bca6k)zj hezxr to the center. Who has the greater angular displacement?

A. the boy

B. the girl

C. Both have the same non-zero angular displacement.

D. Both have zero angular displacement.

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5#

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A boy and a girl are riding on a merry-go-round which is turning at)2 :m*ngnbk vj a constant rate. The boy is near the outer edge, and the girl in)bj2*mgnv: k s closer to the center. Who has the greater angular speed?

A. the boy

B. the girl

C. Both have the same non-zero angular velocity.

D. Both have zero angular velocity.

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6#

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A boy and a girl are riding on /zv d29mgbg ,ta merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater linear speed?tmgzb,dg9 v/2

A. the boy

B. the girl

C. Both have the same non-zero translational velocity.

D. Both have zero translational velocity.

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7#

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A boy and a girl are riding a merry-go-round which is turning at a ck8k iz(k 6cwc*onstant rate. The boy is ne*6 zwc8kk k(ciar the outer edge, while the girl is closer to the center. Who has the greater centripetal acceleration?

A. the boy

B. the girl

C. Both have the same non-zero centripetal acceleration.

D. Both have zero centripetal acceleration.

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8#

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A boy and a girl are ridxu7+obhz 9:b4d,rv y n+2;hr qtu;ykding a merry-go-round which is turning at a constant rate. The boy is near the outer edge, 79ty+nu,;+b;ud:yr4dhv xkhqr o2z b while the girl is closer to the center. Who has the greater tangential acceleration?

A. the boy

B. the girl

C. Both have the same non-zero tangential acceleration.

D. Both have zero tangential acceleration.

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9#

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Consider a rigid body that is rotating. Which ofgrk*r).1twabd ) 4fds the following is an accurate stater .)4 k*rbs aw1dgtfd)ment?

A. Its center of rotation is its center of gravity.

B. All points on the body are moving with the same angular velocity.

C. All points on the body are moving with the same linear velocity.

D. Its center of rotation is at rest, i.e., not moving.

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10#

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Rolling without slippi7duu9nnb6j4 /sq + ozzng depends on

A. kinetic friction between the rolling object and the ground.

B. static friction between the rolling object and the ground.

C. tension between the rolling object and the ground.

D. the force of gravity between the rolling object and the Earth.

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11#

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Two equal forces are applied to a door. The first fw)au pn/6ktzbak9y s1:q6u4 a+vt +ab orce is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces 6v4bq tau+kkywus9 p:1at+z6 b /naa) are applied perpendicular to the door. Which force exerts the greater torque?

A. the first at the midpoint

B. the second at the doorknob

C. both exert equal non-zero torques

D. both exert zero torques

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12#

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Two equal forces are applied to a door at the d yun5u4iezv * czoe 7uy-h(x4.oorknob. The first force is applied perpendicular to the door; the second force z 4y xo.4ue5u-h(ecyu ni7v*zis applied at $30^{\circ}$ to the plane of the door. Which force exerts the greater torque?

A. the first applied perpendicular to the door

B. the second applied at an angle

C. both exert equal non-zero torques

D. both exert zero torques

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13#

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Two forces are applied to a doorknob, pe tzvm2u j,)qnqk)08krkkv 14krpendicular to the door. The first force is twice as large as the second force. The ratio of the torque of the first to the torque of the second is8qnruvk4tk, 0qk))2jm1 k zvk

A. 1/4.

B. 1/2.

C. 2.

D. 4.

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14#

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What is the quantity f94 eup0uyi,an3xn)31; b0jfo) iezax7wd er used to measure an object's resistance to changes in rotation? zpdi3u937 a0ox j1 )ba)re,ux4ie efwnfny0;

A. mass

B. moment of inertia

C. torque

D. angular velocity

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15#

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Consider two uniform solid spheres where 2 (x y0pq.lf7p2tlh itboth have the same diameter, but one has twice the mass of the other. The ratio of the larger moment of inertia to tll7py t (t02.q 2pxifhhat of the smaller moment of inertia is

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16#

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Two uniform solid spheres have the same mass, but one has 28974fok 6qriqgr ovgj* 9o ietwice the radius of the other. The ratio of the larger sphere's moment of inertia to that of the smaller sphere iso rgo6*eq4ri9 v j97o2gkfi8q

A. 4/5

B. 8/5

C. 2

D. 4

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17#

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Consider two uniform solj,*8dqv jgx+)hy nm4ah 54dcyid spheres where one has twice the mass and twice the diameter of the other. The ratio of the larger moment of gd ayh* mh8vy5+)nqc ,j4j4dx inertia to that of the smaller moment of inertia is

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18#

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A uniform solid sphere has mass M and rad2siluc: aw89 cius R. If these are increased to 2M and 3R, what happens to the sphere's moment of inertia about a central axis?: ws29ical8cu

A. increases by a factor of 6

B. increases by a factor of 12

C. increases by a factor of 18

D. increases by a factor of 54

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19#

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If a constant net torque is applied to an h ; ukh*at;jl*object, that object will

A. rotate with constant angular velocity.

B. rotate with constant angular acceleration.

C. having an increasing moment of inertia.

D. having a decreasing moment of inertia.

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20#

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The moment of inertia of a solid cylinder about its axis is ge4x .u12ju2u t7ln/hy+jr apziven by 0.5 MR2. If this cylinder rolls without slipping, the ratio of its rotational kinetic energy to ua yzhj4e272x.1lt nrj/u+up its translational kinetic energy is

A. 1:1

B. 1:2

C. 2:1

D. 1:3

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21#

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Consider a motorcycle of mass 150 kg, one wheel of which ix5du0;,,vkqx20o doxh mg6 m bn2zp- has a mass of 10 kg and a radius of 30 cm. What is the ratio of the r-0x0vxmkqzo 2db,ugdh m2 o;5p ,nxi6otational kinetic energy of the wheels to the total translational kinetic energy of the bike? Assume the wheels are uniform disks.

A. 0.033:1

B. 0.067:1

C. 0.33:1

D. 0.67:1

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22#

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Suppose a solid sphere of mass 6nxd9kst zf -;0 f0q1qmx5pks fv v;o1M and radius R rolls without slipping down an inclined plane starting from rest. The linear velocity of the sphere at the botts1fkz01 5 sxdp; qqv-tf9fo0;m6kxnv om of the incline depends on

A. the mass of the sphere.

B. the radius of the sphere.

C. both the mass and the radius of the sphere.

D. neither the mass nor the radius of the sphere.

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23#

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Suppose a solid sphere of mass M and radius R rolls withpjg-fs /ooes meyp jyt :r0f(1*+ s.2cout slipping down an inclined plane starting from rest. The angular velocity of the sphere at the bottom of the incls-srg12j.myjte*o/ +pc f:p0 eyo fs(ine depends on

A. the mass of the sphere.

B. the radius of the sphere.

C. both the mass and the radius of the sphere.

D. neither the mass nor the radius of the sphere.

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24#

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"The total angular momentum of a system of particles changes when a s/xsr x-r4reht.47rgw vmd :0 net external force acts on the system." This statement w-mrrd/ x4:7rg4shts .r ex0 vis

A. always true.

B. never true.

C. sometimes true. It depends on the force's magnitude.

D. sometimes true. It depends on the force's point of application.

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25#

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In what circumstances can the angular velocity of system of particles change witp6 va 6zk/0vjthout any change in the system's angulavzp v6k atj06/r momentum?

A. This cannot happen under any circumstances.

B. This can happen if a net external force acts on the system's center of mass.

C. This can happen if the only forces acting are internal to the system.

D. This can happen if an external net torque is applied properly to the system.

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26#

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The Earth orbits the Sun in an elliptical orbit. Ignore anyl en*v-ztv )r ra0x7+d friction which may be present. What happens over time to the Earth's angular momentum about*nd7 e+tv-vax )rzlr0 the Sun?

A. It continually increases.

B. It continually decreases.

C. It remains constant.

D. It increases during some parts of the orbit, and decreases during others.

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27#

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The Earth moves about the Sun in an elliptical oimd ntc078hlt(; :cxn-4fixz rbit. As the Earth moves close to the Sun, then which of the following best describes the orbiting speihf;m xit 07 -(dt n8nl4cxz:ced of the Earth about the Sun?

A. increases

B. decreases

C. remains constant

D. none of the above

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28#

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An ice skater performs a pirouette (a fast spin) by pum0y*.shah1kul. nbe- lling in his outstretched arms closem.hy keh-n0bus.a *l1 to his body. What happens to his angular momentum about the axis of rotation?

A. It does not change.

B. It increases.

C. It decreases.

D. It changes, but it is impossible to tell which way.

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29#

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An ice skater performs a pirouette (a fast spin) by pulling xfbz 4ei t n5jxh7:utd2t8b),in his outstretched arms close to his body. What happens to his rotational kinetic energy about the axis:87i z2bnefjtdb,x4hx t)5 tu of rotation?

A. It does not change.

B. It increases.

C. It decreases.

D. It changes, but it is impossible to tell which way.

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30#

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An ice skater performs a pirouette (a fast spin) by pulling inq u890kp nhun( al1 )p:n. hgtncooxrir-368n his outstretched arms close to his body. What happens to his moment of inertia about the axis ofoogaxui-hc(nhn89.p1r)8qunn3lk t n: p6 r0 rotation?

A. It does not change.

B. It increases.

C. It decreases.

D. It changes, but it is impossible to tell which way.

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31#

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State the law of conservation of angular momro/w+q5cwo3 +rx-q a+2n eyzlz sh)/ uentum.

该题自我估分: (必填) (满分:1.0分)

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32#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

What arc length does the Earth travel in a three month period in its nearly c (j+wx.ehb(-d4 6cvrra-xq koircular orbit akx wcvao.j br-4 -rxd6e(q (+hbout the Sun with a radius of $1.5 \times 10^{11} \; m$?

A. $1.2 \times 10^{11} \; m$

B. $1.8 \times 10^{11} \; m$

C. $2.4 \times 10^{11} \; m$

D. $3.0 \times 10^{11} \; m$

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33#

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The second hand of a clock has a length of 0.30 m. What distan;7mf;p,avc c sce does the tip of the second hand sweep through in 3 minutes and 45 sec;am,pc;7c fs vonds?

A. $1.1 \; m$

B. $1.8 \; m$

C. $7.1 \; m$

D. $13 \; m$

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34#

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How many rad/s is 25 revolv/ ov/be ;wvnov*k3g1utions per minute equivalent to?

A. 0.42 rad/s

B. 2.6 rad/s

C. 160 rad/s

D. 240 rad/s

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35#

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A bicycle wheel rotates uniformly through 2.0 revolutions in 4.0 s. Wh ;hf:r28ndpg pc-ukkm9 : zpw1at is the frequency of thepp -d wf;m2zgp1k8n:hk9r: cu wheel's rotation?

A. $0.50 \; Hz$

B. $1.0 \; Hz$

C. $2.0 \; Hz$

D. $4.0 \; Hz$

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36#

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A pulsar (a rotating neutron star) emits pulses at a frequency*r 7 3.kd9g vynohg7ya of 0.40 kHz. The period o 7 nd3.*gyg9 yrvkhoa7f its rotation is

A. 2.5 ms.

B. 2.5 s.

C. 0.025 s.

D. 25 ms.

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37#

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A phonograph record rotates at 45 rpm. Through what anx; pt+ pfp+xq( xsqe452zcyc+gle does it turn in 0.20 zqep++p+5;xqf p x4c2sct(yxs?

A. $9.0^{\circ}$

B. $15^{\circ}$

C. $54^{\circ}$

D. $96^{\circ}$

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38#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of diameter 26 cm turns at 1 t 9naa0;j)b, mwbnlswb:5bg)500 rpm. How far will a point on the outer rim move in ,tm:b awbnls)gjnb wba ;9)502.1 s?

A. $3.1 \; m$

B. $41 \; m$

C. $90 \; m$

D. $180 \; m$

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39#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A bicycle wheel rotates uniformly through 2.0 revol0erv t.wjqd ;(q4kr(g gl9 *qautions in 4.0 s. What is the a.9;ve 4g q(0dwq(jgarrt*k lqverage angular speed of the wheel?

A. 0.79 rad/s

B. 1.6 rad/s

C. 3.1 rad/s

D. 6.3 rad/s

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40#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A bicycle wheel rotates unifo794amw/c58 a5mhi nzwf5diznu tz *-qrmly through 2.0 revolutions in 4.0 s. What is the linear speed of a point 0.10 m from the center of themw85*tuwi59-qdh 5 ia/an4fm c z 7znz wheel?

A. 0.63 rad/s

B. 0.31 rad/s

C. 0.16 rad/s

D. 0.079 rad/s

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41#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A cable car at a ski resort carries skiers a distance of 6 vt3aop-24ljr;rhtd -;il gk ..8 km. The cable which moves the car is driven by a pulley with diameter 3.0 m. Assuming no slippage, how fast must the pulley rotate for the cable car to make the triotk3vpgrl;t.ja2-hi4 - dl ;r p in 12 minutes?

A. $9.4 \; rpm$

B. $30 \; rpm$

C. $60 \; rpm$

D. $720 \; rpm$

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42#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of radius 1.0 m is rotating with a constant angular6h/)fmaka, a jji elc3(9(w zw+oa1 bc speed of 2.0 rad/s. What is the linez/(baf9la,akw) m1e w6+ j o icj(hc3aar speed of a point on the wheel's rim?

A. 0.50 m/s

B. 1.0 m/s

C. 2.0 m/s

D. 4.0 m/s

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43#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

The cutting cord on a gax-/anq 9z1q*u vqw s6us-powered weed cutter is 0.16 m in length. If the motor rotates at the ra*qauv6 qqw 1s-xu/9z nte of 20 rev/s, what is the approximate linear speed of the end of the cord?

A. 20 m/s

B. 25 m/s

C. 35 m/s

D. 65 m/s

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44#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of radius 1.0 m is rotating with a constant angulaol*ryc .bs4ydx bhs;50 a(6m hr speed of 2.0 rad/s. What is the centripetal acceleration of a poi r6 4y.0;oas*5dsbbm hx cyh(lnt on the wheel's rim?

A. $0.50 \; m/s^2$

B. $1.0 \; m/s^2$

C. $2.0 \; m/s^2$

D. $4.0 \; m/s^2$

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45#

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What is the centripetal acceleratclimqrow/,(- )o(qm (vcu 1b cion of a point on the perimeter of a bicycle wheel of diameter 70.0 crm1vlb icomcq,) u (-oc(/(wq m when the bike is moving 8.00 m/s?

A. $91.0 \; m/s^2$

B. $183 \; m/s^2$

C. $206 \; m/s^2$

D. $266 \; m/s^2$

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46#

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How many revolutions per minute (rpm) must a circular, rotating space statiop bjq7 k2u7fdiy,+m; dn (r = 10 2qfm ub,jk 7iyp;7+dd00 m) rotate to produce an artificial gravity of $9.80 \; m/s^2$?

A. $0.95 \; rpm$

B. $0.83 \; rpm$

C. $0.075 \; rpm$

D. $0.094 \; rpm$

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47#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A car is negotiating a flat circular curve o8p xv);fo1cx zf radius 50 m with a speed of 20 m/s. The maximum centripetal force (provx)zpo 8v1c xf;ided by static friction) is $1.2 \times 10^{4} \; N$. What is the centripetal acceleration of the car?

A. $0.40 \; m/s^2$

B. $0.80 \; m/s^2$

C. $4.0 \; m/s^2$

D. $8.0 \; m/s^2$

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48#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A car is negotiating a flat circular curve of radius 50 m wiwcu puh/h(o h:y.i9puk yr505hw3 n1mth a speed of 20 m/s. The mamh pk.u:5h 510uhwr(o cwyh9yipnu3 /ximum centripetal force (provided by static friction) is $1.2 \times 10^{4} \; N$. What is the mass of the car?

A. $0.50 \times 10^{3} \; kg$

B. $1.0 \times 10^{3} \; kg$

C. $1.5 \times 10^{3} \; kg$

D. $2.0 \times 10^{3} \; kg$

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49#

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A 0.300-kg mass, attp5cery l so2j(i42zb7r2kf p2ached to the end of a 0.750-m string, is whirled around in a smooth lfj rbk2 7solre(z 245c y22ppievel table. If the maximum tension that the string can withstand is 250 N, then what maximum linear speed can the mass have if the string is not to break?

A. 19.4 m/s

B. 22.4 m/s

C. 25.0 m/s

D. 32.7 m/s

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50#

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A bowling ball of mass 7.5 kg and radius 9.0 c5 lj4-rpve1 bi5uw3jhm rolls without slipping 10 m down a lane at 4.3vl- pj3541ihrwju eb5 m/s.
(a) Calculate the angular displacement of the bowling ball.   rad ( fill in numbers only)
(b) Calculate the angular velocity of the bowling ball   rad/s ( fill in numbers only)
(c) Calculate the radial acceleration of the bowling ball    $m/s^2$ ( fill in numbers only)
(d) Calculate the tangential acceleration of the bowling ball    $m/s^2$ ( fill in numbers only)

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51#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel accelerates with : :jado/4 v o.h pvb4 e0f+xezqe.9vnna constant angular acceleration of $4.5 rad/s^2$. If the initial angular velocity is 1.0 rad/s, what is the angle the wheel rotates through in 2.0 s?

A. $11 \; rad$

B. $9.0 \; rad$

C. $7.0 \; rad$

D. $4.5 \; rad$

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52#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel accelerates wxcx0:tb6gorqz :o e:. ith a constant angular acceleration of $4.5 rad/s^2$. If the initial angular velocity is 1.0 rad/s, what is the angular velocity at t = 2.0 s?

A. 1.0 rad/s

B. 7.0 rad/s

C. 9.0 rad/s

D. 10 rad/s

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53#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

How many radians does a 0.300-m radius automobile tire rotatrd 5datg dt* dj6mh/(.e(h.ha:(ehho e after starting from rest and accelerating at *(hea: mgehdd t5(.6/d.ao(hh ht jrda constant angular acceleration of $2.00 \; rad/s^2$ over a 5.00-s interval?

A. $1.00 \; rad$

B. $2.00 \; rad$

C. $12.5 \; rad$

D. $25.0 \; rad$

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54#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel starts at rest, an7 4dorgu8x ffbcg *5/kd has an angular acceleration of $4 \; rad/s^2$. Through what angle does it turn in 3.0 s?

A. $36 \; rad$

B. $18 \; rad$

C. $12 \; rad$

D. $9.0 \; rad$

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55#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A Ferris wheel rotating at 20 rad/s decelerates with a constant angular acc7 s3,6k +n rbwyy:.one(du9kfy pa7ereleration ne:pk+r.f7aebsny ku3,7dyw o r69 (yof $-5.0 \; rad/s^2$. How many revolutions does it rotate before coming to rest?

A. 40

B. 20

C. 6.4

D. 3.2

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56#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel starts from rest and reaches an angular speed of 6.0 raox/ pfw:nt+k*d/s while turning through 2.0 revoluti:kotn* pwfx+ /ons. What is the average angular acceleration of the wheel?

A. $0.24 \; rad/s^2$

B. $1.4 \; rad/s^2$

C. $3.0 \; rad/s^2$

D. $9.0 \; rad/s^2$

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57#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of diameter of 68.0 cm slo ; )jq fbfr07*cbby2oows down uniformly from 8.40 m/s to rest over a distance of 115 m. What is the total number of revoboj7)b0f*yf ;r bqco2lutions the wheel rotates in coming to rest?

A. $53.8 \; rev$

B. $26.9 \; rev$

C. $338 \; rev$

D. $169 \; rev$

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58#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of diameter of 68.0 cm slows down uniformly from 8.40 m/s t8yal) , stswv-o rest over a distance of 115 m. What is the angular acceleratios-l,wys) atv8 n?

A. $-1.80 \; rad/s^2$

B. $-0.90 \; rad/s^2$

C. $-5.65 \; rad/s^2$

D. $-11.3 \; rad/s^2$

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59#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of diameter of 68.0 cm slows down uniformly from 8.40 m/s lc vluq-wkjt344 s)-f) ap1s nto rest over a distance ovnk cll-s uja4)s q)4w p1t-3ff 115 m. How long does it take for the wheel to come to the stop?

A. $24.7 \; s$

B. $27.4 \; s$

C. $42.7 \; s$

D. $47.2 \; s$

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60#

Fill-in-Blank ( 1.0 marks) Whole-Paper View Save Problem

A centrifuge in a medical laboratory rotate+h0w xi2fay7lee,6cjs at a rotational speed of 3600 rev/min. When switched off, it rotatayjf6x we+h2,c7 i 0lees 50.0 times at a constant angular acceleration before coming to rest.
(a) Determine the initial angular speed of the centrifuge.    $rad/s$
(b) Determine the angle (in radians) through which the centrifuge rotates before coming to rest.    $rad$
(c) Calculate the constant angular acceleration of the centrifuge.    $rad/s^2$
(d) Calculate the time necessary for the centrifuge to come to rest.    $s$

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61#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

The bolts on a car wheel require tightening to a torque v:**u7nfc 10uj/o es7l+ ftfhsw ysi/ of 90 Nm. If a 30 cm long wrench is used, what is the magnitude of the force required when the force applied as/ oul t1* n*7suj/+cws7hv: yfif0f et $53^{\circ}$ to the wrench?

A. $190 \; N$

B. $380 \; N$

C. $19 \; N$

D. $38 \; N$

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62#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel with moment of inerti/r v7s 8qt*cvb 1nrws/a $3.00 kgm^{2}$ has a net torque of 3.50 Nm applied to it. What angular acceleration does it experience?

A. $0.857 \; rad/s^2$

B. $1.17 \; rad/s^2$

C. $3.00 \; rad/s^2$

D. $3.50 \; rad/s^2$

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63#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A triatomic molecule is modeled a* iher +);e9ht fuyeb(s follows: mass m is at the origin, mass 2m is at x = a, and, mass 3m is at;+rh ue e9byitf*)(he x = 2a. What is the moment of inertia about the origin?

A. $2 ma^2$

B. $3 ma^2$

C. $12 ma^2$

D. $14 ma^2$

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64#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A solid cylinder of mas0 i.h .(wac 5nk8(1emhfnqbm ss 10 kg is pivoted about a frictionless axis thought the center O. A rope wrapped around the oc8n0 1kheb..((af 5qnhmswimuter radius R1 = 1.0 m, exerts a force F1 = 5.0 N to the right. A second rope wrapped around another section of radius R2 = 0.50 m exerts a force F2 = 6.0 N downward. (See Fig. below) What is the angular acceleration of the cylinder?

A. $1.0 \; rad/s^2$

B. $0.60 \; rad/s^2$

C. $0.40 \; rad/s^2$

D. $0.80 \; rad/s^2$

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65#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A solid cylinder of mass 10 kg is pivoted about a frictionless axis thought tdyc4 t wwv7rcain09p4 lcl22- jonv44he center O. A rope wrapped around the outer radius R1 = 1.0 m, exerts a force F1 = 5.0 N to the right. A second rope wrapped around another sectiovi2nr 4w4 0llp4j4no w9cc cat -7yd2vn of radius R2 = 0.50 m exerts a force F2 = 6.0 N downward. How many radians does the cylinder rotate through in the first 5.0 seconds, if it starts from rest?

A. $13 \; rad$

B. $7.5 \; rad$

C. $5.0 \; rad$

D. $10 \; rad$

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66#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A 4.00-m long rod is hinged at one end. The foasg 9zp2u wyz/81 io31imvz5 c d-:jrod is initially held in the horizontal position, and then released as the free end is allowed to fall. What is the angular acceleration as it is released? (The moment of inertia of a rod about one end is ML21im: 8puo-y /dgjvfz2wo15z9 3z asci/3.)

A. $2.45 \; rad/s^2$

B. $3.68 \; rad/s^2$

C. $4.90 \; rad/s^2$

D. $6.75 \; rad/s^2$

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67#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

Consider a bicycle wheel56*xxu5oxhw v to be a ring of radius 30 cm and mass 1.5 kg. Neglect the mass of thv *xxh6 x5ou5we axle and sprocket. If a force of 20 N is applied tangentially to a sprocket of radius 4.0 cm for 4.1 s, what linear speed does the wheel achieve, assuming it rolls without slipping?

A. 3.0 m/s

B. 5.9 m/s

C. 7.1 m/s

D. 24 m/s

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68#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A 1.53-kg mass hangs on a rope wrappedv 5q:9;g wi0 hq0a qz3tjpx1ojb;r) kh around a frictionless disk pulley of mass 7.07 kg and radius 66.0 cm. What is the angular acceleration of thwtqjh10o9q hij5;)vpq:3 zg0;xk a bre pulley?

A. $4.49 \; rad/s^2$

B. $7.98 \; rad/s^2$

C. $9.87 \; rad/s^2$

D. zero

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69#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A 1.53-kg mass hangs on argzoi8 .4j;fy rope wrapped around a frictionless disk pulley of mass 7.07 kg and radius 66.0 cm. What is the ioy.8;gz 4rjf acceleration of the mass?

A. $9.26 \; m/s^2$

B. $2.96 \; m/s^2$

C. $6.29 \; m/s^2$

D. zero

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70#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A rotating flywheel can be used to store energy. If it is required to stl/k t0q6o(ltwfx6)re ore $1.00 \times 10^{6} \; J$ of energy when rotating at 400 rad/s, what is the moment of inertial of the wheel in $kgm^{2}$?

A. 6.25

B. 12.5

C. 25.0

D. 50.0

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71#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A wheel of moment of in32lkr 5oh( pqgz z70uqertia of $5.00 \; kgm^{2}$ starts from rest and accelerates under a constant torque of 3.00 Nm for 8.00 s. What is the wheel's rotational kinetic energy at the end of 8.00 s?

A. $57.6 \; J$

B. $64.0 \; J$

C. $78.8 \; J$

D. $122 \; J$

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72#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A solid sphere of mass 1.0 kg and radius 0.010 m starts from rest and rolls(: xy0 nonpypj-(( k-f h6rmps without slipping down0 r jo:(h- fxpynnp(k-yps6(m a 1.0-m high inclined plane. What is the speed of the sphere when it reaches the bottom of the inclined plane?

A. 3.7 m/s

B. 4.4 m/s

C. 5.6 m/s

D. 6.3 m/s

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73#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A solid sphere of mass 1.0 kg and radiushjds2 g4 2b-d;pk9u. de z;fch 0.010 m rolls with a speed of 10 m/s. How high up an inclined plane can it climb before coming to ruhjgsdbdf9h-2 ;4dz;k . 2pec est?

A. $0.071 \; m$

B. $0.71 \; m$

C. $7.1 \; m$

D. $71 \; m$

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74#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A hoop of radius 0.50 m and a mass of 0.20 kg is released from r .,6b t ceis7/, oe8qbag*xgubest and allowed to roll down an inclined plane. How fast is it moving after dropping a vert.ucs7bo8g q 6b exbeg/ *ai,,tical distance of 3.0 m?

A. 2.2 m/s

B. 3.8 m/s

C. 5.4 m/s

D. 7.7 m/s

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75#

Free-Response ( 1.0 marks) Whole-Paper View Save Problem

A solid sphere of mass 1.5 kg and radius 15 cm ro1 qna*6 xzr+zcluw 4,glls without slipping down a 35e incline thal*znzx 64g,r+uq1w c at is 7.0 m long. Assume it started from rest. The moment of inertia of a sphere is given by $I = (2/5)MR^2$.
(a) Calculate the linear speed of the sphere when it reaches the bottom of the incline.
(b) Determine the angular speed of the sphere at the bottom of the incline.
(c) Does the linear speed depend on the radius or mass of the sphere? Does the angular speed depend on the radius or mass of the sphere?

该题自我估分: (必填) (满分:1.0分)

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76#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

An object's angular momentum changev3+d 7( jpyafd y* ( hvvvyz8o/krfe5ran7)i* s by $20 \; kgm^{2}/s$ in 4.0 s. What magnitude average torque acted on this object?

A. $2.5 \; N \cdot m$

B. $5.0 \; N \cdot m$

C. $40 \; N \cdot m$

D. $80 \; N \cdot m$

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77#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A proton of mass $1.67 \times 10^{-27} \; kg$ rotates with an angular speed of 2 x 106 rad/s in a circle of radius 0.80 m in a cyclotron. What is the orbital angular momentum of the proton?

A. $1.28 \times 10^{-21} \; kg \cdot m^{2}/s$

B. $1.76 \times 10^{-21} \; kg \cdot m^{2}/s$

C. $2.14 \times 10^{-21} \; kg \cdot m^{2}/s$

D. $3.20 \times 10^{-21} \; kg \cdot m^{2}/s$

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78#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

An ice skater has a moment of ivf5 j0ktv c-0rnertia of $5.0 \; kgm^{2}$ when her arms are outstretched. At this time she is spinning at 3.0 revolutions per second (rps). If she pulls in her arms and decreases her moment of inertia to $2.0 \; kgm^{2}$, how fast will she be spinning?

A. $2.0 \; rps$

B. $3.3 \; rps$

C. $7.5 \; rps$

D. $10 \; rps$

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Mark Problem

79#

Single-Choice ( 1.0 marks) Whole-Paper View Save Problem

A figure skater rotating alm9r, ap xa8ie;rh78ee /;lik t 5.00 rad/s with arms extended has a moment of inertia rlm9ae8ire p;x,l/;h8e ak7iof
$2.25 \; kgm^{2}$. If the arms are pulled in so the moment of inertia decreases to $1.80 \; kgm^{2}$, what is the final angular speed?

A. 2.25 rad/s

B. 4.60 rad/s

C. 6.25 rad/s

D. 0.81 rad/s

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