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

1#

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Angular displacement is usuallz(ama*wo j -(ry express in units of

A. meters.

B. radians.

C. revolutions.

D. arcs.

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2#

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Angular velocity is enlts9a-) vc (z9 uiww:wh,gx3 xpressed in units 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 ul9azh 6 ud2bk1,olz8p2 :jcp rnits 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 turning at a constantrxeu2tdvest: 0m-3 5q m lz2t- rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greaxml:d5-2erv sqt-3ezt 2u0m tter 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-godnf 4:x xop;g0qot8xat7d -c0-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who hastx0g0:oo np7x ; dfatc d84xq- 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 a merry-go-roj m2(n)i* m bkfgji4b0t ug0(mund which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who haji2n gb4g0u(m kmfb)*( m jt0is the greater linear speed?

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 mejtq0g3 9 swwdpvyp 9xu+.r6 l0rry-go-round which is turning at a constant rate. Thewx0+ywppt l.39jrgvusqd 096 boy is near 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 riding a merry-go-round which is turning at a constant ww3c5xj r5xh4rate. The boy is near the outer edge, while the girl is closer to the center. Who hasjhrx5w5w xc43 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 of the following is avkq.) iiqtg7c6+7rae9+/pmm7k tsx wn accurate stateme)iqqt xk+ +9ae 6.7/s7 vrgmkmt7wp cint?

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 slipping dep8ihtu23(v j+d 5ru clahhzf.)ends 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 fod:gl087qu on;i7mre ) egj)tv rce is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicue0:n8j ig)veg )lr7 qmdo;ut7 lar 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 wrbq fq71j6x6cu /n*6jzo 9ey/mh1aeapplied to a door at the doorknob. The first force is applied perpendicular to the door; the second force is app9 6hq e*xonema/f/ 1uzr6 yc7qjwb61jlied 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, perpendicular to the door. The first for) d*kwr2lu j3yce is twice as large as the second force. r2k j dw*3lyu) The ratio of the torque of the first to the torque of the second is

A. 1/4.

B. 1/2.

C. 2.

D. 4.

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14#

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What is the quantity used to measure an object's7gup()3mzhq )ddc.uo resistance to changes in rotatio)3odc ()dup .g qhu7mzn?

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 both a6 ( 3sdsk;hhkhave the same diameter, but one has twice the mass of the ot3;k ss(hdah6k her. The ratio of the larger moment of inertia to that 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 twice the radius 9*ctu3c3.jm pe7 iyipof the other. The rati9tyii7e*cp c.p3 u jm3o of the larger sphere's moment of inertia to that of the smaller sphere is

A. 4/5

B. 8/5

C. 2

D. 4

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17#

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Consider two uniform solid spheres where one has twice th k,v)*p* x,c mnzad,8 utp ,pqqkpg5 u:okbx6-e mass and twice the diameter of the other. The ratio of the larger mox8onp kpgu6 * ,cq,-pxmk,5k,) zpuvb*q: atd ment of 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 ++n2kt n0 tlyho * /3dzvuwk:fand radius R. If these are increased to 2M and 3R, what happens to the sphere's moment of inertia about a central axis f2 nozv+3un/ydl:t+w 0 hktk*?

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 objec eby ,dl1q7f;fz6z:1kkq b dx+t, 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 cp)jjk;)9wcp fkq qovftz 73; h8 kci(;ylinder about its axis is given by 0.5 MR2. If this cylinder rolls without slipping vp qcfik9 ;c(wk;ph3kjj o;t))qzf78, the ratio of its rotational kinetic energy to 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 h0o;w coiah(u..m 8li zxdvp7t ;z5 l,las a mass of 10 kg and a radius of 30 cm. ix,w z;vthli;l87.cdo.(l 5 oza0pm u What is the ratio of the rotational 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 M and radius R rolls without 1w+q yiyrkh ,bk(h2/9 pt9xdtslipping down an inclined plane starting from rest. The linear velocity of the sphere at the bottom of the incline dependsrh/iw92t91y kthxydk b(+,qp 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 pfvg1g) pb ,6u1n4zkdmass M and radius R rolls without slipping down an inclined plane starting from rest. The angular velocity of the sphere at the bot 1pdp, nfu b16v4z)kggtom 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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24#

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"The total angular momentum of a system of particles changes r9wwi4a lwsw*i72gqhcx7yv 2s 7 w i4(when a net external force acts on the system." This stat7i wsr742 ywgwqch2*a( xs7vwil4i9wement is

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 chando*f 9h* 7 .y)yqa0.cgxycrb dge without any change in the system's angular momentum.)0yqaydc* fx 7r h*y dcb.9og?

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 qq4i;n 5v.a chSun in an elliptical orbit. Ignore any friction which may be present. What happens over time to the Earth's angular cv .aqhn;iq54momentum about 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 orbit. As th o3zh3x7 pkms4e Earth moves close to the Sun, then which of the f7o4mx3sph3kz ollowing best describes the orbiting speed 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 pirouettelhvz 0 zc*53x3dj6*m trqeh/j (a fast spin) by pulling in his outstretched arms close to his bodtxhd63qv lrmcz3* z/h0jej5*y. 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 pirouetihocupxf -5u1+m4xh 9 te (a fast spin) by pulling in his outstretched arms close to his body. What happens to his rotational kinetic energy aboxhucu4mp+ h9i-5 ox1 fut 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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30#

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An ice skater performs a pirouette (ck p+s39 *bh8*js fdwsa fast spin) by pulling in his outstretched arms close to his body. What happens to his moment of inertia abwp9f sh+b* jcd s8*sk3out 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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31#

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State the law of conf8igchq uog7ie ejz 8(+6-sd9 servation of angular momentum.

该题自我估分: (必填) (满分:1.0分)

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32#

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What arc length does the Earth travel in a three month period in its nenz.m8+(. z kj,ewc smharly circular orbit about thw.hsz,.e ncm(m j8kz+e 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. Wh k-ykz2yis-dp ft;p( /at distance does the tip of the second hand sweep through ;kfp2tz/ips(-yk- y din 3 minutes and 45 seconds?

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 revolutions per minute equivalent nt9-:c cztm3k(mjrv. 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 unif;qqds.: b pb5vormly through 2.0 revolutions in 4.0 s. What is the d bbqv:q.5s;p frequency of the 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 of 0.40 ni(dq) 4vq,r;x ubcy3 kHz. The period of iq,dx()quc v3nyb 4i;rts 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 l6g vpjmb.o 79 8pyko:at 45 rpm. Through what angle does it turn in 0.20 s?pjgo p mb89l:kyvo6. 7

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 1500 :s ,gbre,bcl6v*v c-l rpm. How far will a point on the outer rim mov-eg*:bv,bsvcl rl,6c e in 2.1 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 revo px.sz0jh:(rbw3 iv3c/3pyp olutions in 4.0 s. What is the average angular speed of p:pp0/s b(wc y o3 3xz.hirv3jthe 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 uniformly through 2.0 lmpixpmx: 4 (p k(,ok4revolutions in 4.0 s. What is the linear speed of a point 0.10 m from the center of the whek m(:lmkpx(ox p,p4i4el?

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 4kunph q2 hif0ep:2 p)of 6.8 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 q puf2h:42pnkp ih)0ethe cable car to make the trip 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 withdr8q* g*(oc fzq(p31vj upi 1d a constant angular speed of 2.0 rad/s. What is the line*jq( ivf1u1*p pcq zdrog(8d3 ar 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 gas-poweredci9 n..h6m 3n9dhoirz weed cutter is 0.16 m in length. If the motor rotates a nir3.hi.c9 nzdo6h9 mt the rate 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 angular speed/a3481. apugdyew efl of 2.0 rad/s. What is the centripep/8u ae d1a.efgwyl43tal acceleration of a point 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#

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

What is the centripetal accef5uj7*oe8i6 1sbn9b ozvmkdw c 8g1c2leration of a point on the perimeter of a bicycle wheel of d12oonkmb b 8wde8 zu1cfc5sij7*v69g iameter 70.0 cm 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 station (r o nc *s5*i5it0vhq u/ gs,o5b6su1rwt = 1000 m) rotate to producs*gi*u0n15qtu ob cs,/5t5vi6sow hr e 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 of radius 50 m with a speed of 206 uhkx .d)e3:p hl3hfm m/s. The maximum centripetal force (providfl x ph6m3u.e )h3hk:ded 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 ofd.wwro7 n(u(h radius 50 m with a speed of 20 m/s. The maximum centripetal force (provided by static fd ow(ruh(w. 7nriction) 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#

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

A 0.300-kg mass, attached to the end of a 0.750-m string, is whirled aroqkjm o. /h-*jjund in a smooth level table. If the maximum tension that the string can withstand is 250 N, then what majm*hjojq/- .kximum 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#

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

A bowling ball of mass 7.5 kg and radius 9.0 cm rolls without slip* 9 6zmhi p6gcf3pl jm .nxx)qk(cut*7ping 10 m down a lane at 4.3 69 3p7x.pmztuiq*nkg* )hm6 cj(flxcm/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 a constant angular accelw.z2gbpg 2/ )n7,9au ug2y:ijltu zhmeration 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 with a consvn4uc m48q jd9; cj1ngtant 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.s/qy7q bi,4mx300-m radius automobile tire rotate after starting from rest and accelerating at a constant angulary4i/ s qq7m,xb 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, and has an angular accel)ln elw,(gqz/ zkre*,p91 t vferation 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 cons/gx9:yj6bgr:fa n wh) tant angular acceleration :n6j9 fg /hx :grawby)of $-5.0 \; rad/s^2$. 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 rad/s while t zr,;9rqav3 tbb i8 h1ue clmmqke707- evz37purning through 2.0 revolutions. What is t eukmvvh;177qa, z 3pb 09 zb reelcr83i-q7tmhe 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 slows downh 0kew pp5avv*-ae23a;bys (m uniformly from 8.40 m/s to rest over a distance of 115 m. What is the total number aa *beapk vs e-2wvmyp(350;h of revolutions 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 8v .,use4lf02yiry rps ;.xz9d .40 m/s to rest over a distancy u .sxd.isvy pz2f0r; ,9rel4e of 115 m. What is the angular acceleration?

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 4la bf788rdf .k6zn pidown uniformly from 8.40 m/s to rest over a distance of 115 m. How long does it take for the wheel to come to the stop6.bpl8drfknz a8if 74?

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 rotates at a rotationmc; a-t;k36x )*-ze gru qq 0b.vnrokyal speed of 3600 rev/min. When switched off, it rotates 50.0 tq;m*kvy bn 06;arqogxe)- u-3tzkc.rimes 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 of 90 Nm. If a *uy c/ r,m;at/sns72tsdx 3 do30 cm long wrench is used, what iscss2m ut;,r *n/7 ads/dxyo3t the magnitude of the force required when the force applied at $53^{\circ}$ 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 inlo66 f- h3p-)c.rp qxwzw t0j3 tnta9wertia $3.00 kgm^{2}$ 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 as follows: masvrzd /)tt6 kr4q7 hl8)rrsf/s s m is at the origin, mass 2m is a)s/7q8r z/ tfv)dt lrsrr h4k6t x = a, and, mass 3m is at 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 mass 10 kg is pivotednjp 2 labb41/a about a frictionless axis thought the 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 section of radius R2 = 0.50 m exerts a force F2 = 6.0 N downward. (See Fig. below) What is the angular accele4pb1/a lb a2jnration 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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Mark Problem

65#

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

A solid cylinder of mass 10 kg is pivoted about a frictionless axis to 5 ,gmm(fuey1hought the 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 section of radius R2 = 0.50 m exerts a force F2 = 6.0 N downward. How many radians does the cylinder rotate through in the1u(fg5,m ey om 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. i6 e0+l7 ho497vlfu(fp wib ra1m1ovlThe rod 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 19vopfmi(rw 1u7l0647a bl fe+ iolv habout one end is ML2/3.)

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 wheel to be a ring of radius 30 cm and mass 1.5 :1d53r pvqv tjv0pol -kg. Neglect the mass of the 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 slippijvp v30-1 ordtqp: 5vlng?

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 wrapped agifivcd/no epn6l5 ;i 2i:3 f8round a frictionless disk pulley of mass 7icnf82 f ;v i:inl p3d/g6o5ie.07 kg and radius 66.0 cm. What is the angular acceleration of the 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 a rope wrapped around a frictionless disk pulley of massbtt. :b9+ cc-qymb-nz 7.0nmcq -+cyttb :9.zbb-7 kg and radius 66.0 cm. What is the 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 requi*7k huw4u (od;xex. xa( iz9abred to store $1.00 \times 10^{6} \; J$ 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 inertx v7xey)upk,s(u1 4um ia 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 wit0- epwez 3e+ lg90mhirhout slipping down a 1.0-m high inclined plane. What is the speed of the sphere when it reaches the bog90r z3phie wle-0me+ ttom 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 radius 0.010 m rolls wv-3pvd j zmho5)js w:)ith a speed of 10 m/s. How high up an inclined plane )vj -md3s5h)zw opvj: can it climb before coming to rest?

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 (z: i,hrg2 pbxmja-*va mass of 0.20 kg is released from rest and allowed to roll down an inclined plane. How fast is it mov -j *zi,avpmr:2bhg (xing after dropping a vertical 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 rolls without slipping x 9a 5 o;eyftc(z6 :gyfxffv67down a 35e incline that is 7.0 m long. Assume it started from rest. The moment of inertia of 6 ac5f( e;f fzot97g yx:xvfy6a 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 changeezz6 ,q11mx5ivy.ium rd. dg*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 m1sba f3aht. 8goment of inertia 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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79#

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A figure skater rotating at 5.00 rad/s with arms exte,*q3mey;na jxf+2u y9 lgz.sbnded has a moment of inertiayyfgm2l;*u xq.,+nb az se93j of
$2.25 \; kgm^{2}$. 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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