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

1#

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Angular displacement is usuall9njrgf -gj:e/-hg/ jly express in units of

A. meters.

B. radians.

C. revolutions.

D. arcs.

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2#

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Angular velocity is ek.r ftzy,.e 9/+tahj jv3dah4xpressed 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 exprespdcp3t +,q1dxlbxp2 / sed in units 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 constan tzss 09z1kmu:upn, -ct rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater anp:skuzn,9c1mu-sz 0 t gular 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-roufvx9 7m( dqr d:wmk)i0nd which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the centervq7f ixr 0m k)ddw(:9m. 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 v5w fi fq,5 1s0tmdgn+a 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. 1,mg vndiws+q5f 5tf0Who has 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 merry-gom y)0 admb8pi4tyq4l*-round which is turning at a constant rate. The boy is near m0yymi*q tdp l )8b44athe 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 whic usa5de4v9( t wz6vd- 1unz;tzh is turning at a constant rate. The bo6 ; t 9edwu-s1z(n5v4utvzzad y is near the outer edge, 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 hn (.;2gkabg hrotating. Which of the following is an accurate statement?h b.h( gnag2;k

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 depend7rgx 9c;th7w)b :5bqsoc w px/s 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)3:wgdkk j7cn.uu7 x)knzuphl0f g2mqt+/) a force is applied at the midpoint of the door; the second forcpk7 2)g7wd jg nx+ um:)qfhn3lut0a kcu.)/zke is applied at the doorknob. Both forces 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 doorknob2z k)ag2 wtnl/jqx se8/vn-o; . The first force is applied wgv 8e; lx k)jt22szqnan-o//perpendicular to the door; the second force is 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, peri tj3jm v-b28)0 wythdpendicular to the door. The first force is twice as large as the second force. The ratio of the torque of the first t hbttj-i 2mjy0)w38vdo the torque of the second is

A. 1/4.

B. 1/2.

C. 2.

D. 4.

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14#

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

What is the quantity used to m.und z3tz3 6 f(2ncddzeasure an object's resistance to changes in rotation?t .6 (zz3uzncd3d2 dnf

A. mass

B. moment of inertia

C. torque

D. angular velocity

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15#

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Consider two uniform solh6a1 pgbta/x8l0+s se+y rhc3id spheres where both have the same diameter, but one has twice the mass of the other. Thelp+s+aaex63 08hy/cb rs1h tg 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 tzuj/-cew5z( x.jka x0/:x wurwice the radius of the other. T(kj xx ru5z . 0:jcaw/euzx/-whe ratio 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 the mass and l/ bzcq8b 9nphuf +f+3twice the diameter of the other. The ratio of the larger moment of inertia b+z9c bqn/ uhlff3+8 pto 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 radius R. If these are increased to 2.rwd/ey-z+n yzkuw -jq .:f)g M and 3R, what happens to the sphere'sfz- ww-d.q )j+y ku/:.ryzgen moment of inertia about a central axis?

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 objecfa; xaxn:o-a+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 cyli 9g er(gab em4rvmpv/e.1w)m4nder about its axis is given by 0.5 MR2. If this cylinder rolls without slipping, the ratio of its rotational kinevep.gvg/erm4 m)9ar bw(41e mtic 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 has av)zxb 8gbd 6y ryy: (hh*utg)-t ge,v) mass of 10 kg and a radius of 30 cm. What is the ratio of vd:z,gtey8y*bbg ygv)r )xu(t) 6 hh- 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 R3w y+jmv up)sejc:( l( rolls without slipping down an inclined plane starting from rest. The linear velocity of the sphere at the bottom of the incline dm us)pyl je:v(j(3+ wcepends 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#

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

Suppose a solid sphere of mass M and radius R rolls wia83 llmpjw02ca e 5*ptthout slipping down an inclined plane starting from rest. The al cp502 p*talawj83e mngular velocity of the sphere at the bottom 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 when a jlul p-1-db; 2ybp *biah;yv-net external force yblj--*hv;padb 2y;-bpiul1 acts on the system." This statement 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 velo i7blc t138d ; nf;npd(fk7mmqcity of system of particles change without any change in the system'sli; ncfm7b 8k 73qdn(mdf;1tp angular 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 any friction whe,zlkhw ,7bpi,b+ vn4j.l a b5aa-o 3oich may be present. What happens over time to the Earth's angular momentum about the S.wn5l jz +i,b4 apk,ehlavo3 ,o ba7b-un?

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 the Earth mk ggb1mtv//y d(foo .3oves close to the Sun, then which of the follk/(/v1 ogyom t 3fdb.gowing 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 pirouette (a fast spin) by i *+29 qi pm1av,uvubdpulling in his outstretched arms close to his body. What happens to his angularqp, m21vii9v+d*u u ba 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 in hiubnkn gp(0bx8 q 2v.l9s outstretched arms close to his body. What happens to his rotational kinetic energyb v.2 gpluq9kb8n( n0x 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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30#

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

An ice skater performs a pirouette (a fast spin) t5 qgeis)**ec.fi l(. si y1ntv;+kveby pulling in his outstretched arms close to his body. What happens to his moment of inertia about the ts k*vi)cv.y1 +qs.(;eefilt n*eg5iaxis 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 conservation of ango8ht5l) gu 9zjv9xa*xular 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 g mq*.f2gus 1; fccub1drh(k*nearly circular orbit about the Sun with a radisf*fkc(gru g*2. duh m b;1qc1us 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 3 *iv/d+coqd q -w(onrclock has a length of 0.30 m. What distance does the tip of the second hand sweevdo(dq+ q/nr -c*w3iop through in 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 equivjy41hst) ec 4galent 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. What is thecwliv6 uac gt,l dmf4*u0 48 l*m/w7zq frequency of the whee,4 8aft/wgi7lmd0l* uv4cz c6w q lmu*l's rotation?

A. $0.50 \; Hz$

B. $1.0 \; Hz$

C. $2.0 \; Hz$

D. $4.0 \; Hz$

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36#

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

A pulsar (a rotating neutron star) emits pulses at a frequency tv au6-6gvm:d of 0.40 kHz. The period of its rv ad-:6m6vg tuotation is

A. 2.5 ms.

B. 2.5 s.

C. 0.025 s.

D. 25 ms.

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37#

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

A phonograph record rotates at 45b5v3w4j.j m ;eqjb ep- rpm. Through what angle does it turn in 0.20 -4b bqpj je3vewm;5j.s?

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 tureh2 p22 sgr;aons at 1500 rpm. How far will a point on the outer rim m grosh2a;e 2p2ove 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 revolutions in 4.0;vv/g kr d. p6lr4w 6* nyokk,w*srd8wd /roi3 s. What is the average angular speed of the whee6rlvo ddn go3k *dkrk4rp8w/vw ,.6/i rws ;*yl?

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 revolutions in 4.0 s. What is ,rn 7f1z,ux3km0 fih ithe linear speed of a point ih 103u7iz f,fxk,nrm 0.10 m from the center of the 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. p6bp l5*xwb+p1yvr t carries skiers a distance 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 the ca.5p6pt y+pwrb* xlbv1 ble 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.)0dq 1nxrq1ke o;n sjzg/:b/b 0 m is rotating with a constant angular speed of 2.0 rad/s. What is the linear speed of a point on the wheel's 1noj/kzqn1;/e srxd:0g)bqb 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-powered weed cutter is q:m0fdzpx 41g 0.16 m in length. If the motor rotates atx1 :p4z 0fgmdq 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 3iq-ikv:,-upslc- b m angular speed of 2.0 rad/s. What is the centripetal acceleration of a poi-: qc,v -ls3p-biumk int 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 acceleratilu;45 :8 v -ckdazmghmon of a point on the perimeter of a bicycle wheel of duh;8 54:l gmd mzcakv-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#

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

How many revolutions per minute (rpm) must a circulvzn 5;rw43wlj0 0bfex ar, rotating space station (r = 1000 m) rotate to produce an artificialnf;j3 zlwx40v web0 5r 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 8 9)lspnjmj46yyf l;c speed of 20 m/s. The maximum centrify)8j; 4ls69 ync jpmlpetal force (provided 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 with a speed of 20 m) ( *7j) sqpsjkcua 2q3u8a )-vvfwzyf/s. The maximum centripetal force (provided by s))vz7 wq aq)c(ks8*fu ajuj fv32 s-yptatic 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#

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

A 0.300-kg mass, attached to the end of a 0.750-ma )jwu1ea9-w w string, is whirled around in a smooth level table. If the maximum tension that the string can withstand is 250 N, then what maximum linear speed can the mass have u- w91aaeww)j 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 agrj78 /, :lbns xbx1zond radius 9.0 cm rolls without slipping 10 m down a lane/o xs g r:n,8b71lzjxb at 4.3 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 a constant angular acceleration oftjpfb/oe;ji ;tca 0 --m)wl 4g $4.5 rad/s^2$. 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 constant angular acceleration ofj1kjms ;,wct,c(rvb0ld7vk gcd+4w 3 $4.5 rad/s^2$. 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-mguy* ud)y;l:y radius automobile tire rotate after starting from rest and accelerating at a constant and*g u)yyy: ul;gular 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 accz /l1ps 3jiz)5c6eiwmwi1 nxpw 8g3 ix ,-1zeteleration 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 angulario ),0u(pug sv acceleratu)(pg0ov i ,suion 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 re /em0)cow7f6fl 7eulg 3eytt: aches an angular speed of 6.0 rad/s while turning through 2.0 revolutions. W t/ ucetee f7f0w)glo7y3m:6lhat 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 slows down uniformly from 8.40 m/s to rest over a eyu3 a (nwvj/y*kjr;6 distance of 115 m. What is the total number of revolutions the wheel ry/ej(*u va63jrnwy ;k otates 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 o)wgy07xlbq l24rmsx,p ;k (vpb6 al4 if 68.0 cm slows down uniformly from 8.40 m/s to rest over a distance of 1vp( ,4a)qg6; 0lm2xl w7py rksx bl4bi15 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 down uniformly from 8.40 m/s to rest ov:mh+75 / x seqhz 8l,vxsnweo,er a distance of 115 m. How long does it take fv m8qx,h, heslz7wx:+/ osn e5or 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 v(-h0ruo9wqydj8uo ;laboratory rotates at a rotational speed of 3600 rev/min. When switched off, it rotates 50.0 times at a constant angular accel8o u jrdy9 (u0hq;ow-veration 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 w5ahh46(r*3x ddp+ows vvz p+gheel require tightening to a torque of 90 Nm. If a 30 cm long wrench is op gv++5sddh*346r(az hp xwv used, what is 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 1 usxht3j2u 0jgdlu1:inertia $3.00 kgm^{2}$ 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 )e0(ovfsuh3; i p. qvamu0esf7c fv,5 as follows: mass m is at the origin, mass 2m is at x = a, and, mass 3m is at x = 2a. What is the moment of inertia)fue,pf m 5 us7hs.vve3o(fqi ;v0 ca0 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 pivoted about a frictionless axis thought li1/2;gifn8x ea0idk the center O. A rope wrapped around the outer radius R1 = 1.0 m, exerts a force F iki2nefx10dli ;a8/g 1 = 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* -xtivit8,f 8ts8u;(cc avfy 10 kg is pivoted 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. ,( f xs*t;-vy8itvauf ic8t 8cHow 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.g r3jky5hvo 12 The 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 inertia1h25j3rk ogvy of a rod about 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 radiusyl2 kz3tb z*+b 30 cm and mass 1.5 kg. Neglect the mass of the a*2tyz+ klbbz 3xle 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 wrapx8mvb *+r6crsk- 5vvs ped around a frictionless disk pulley of mass 7.07 kg and radius 66.0 cm. What is the angular acceleration of th8* 6bk r v-rxvs5svmc+e 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 v+ by thiszmb0szk6,)8tl- 9qmass 7.07 kg and radius 66.0 cm. What is the accel )-zks9b0btq+ l iy,vtzmh86seration 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 it5mj +fif6q7i r is required 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 inertia of h+txza.; . g, axga+yi$5.00 \; kgm^{2}$ 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 resky-b y9obxy 1;t and rolls without slipping down a 1.0-m high inclined plane. What is the sy-yyb x;19kb opeed 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 radius 0.010 m rolls with a sph1i pzh jus5ri ;nxj2:2a3bi0 eed of 10 m/s. How high up an inclined plane can it climb before comibu h2z;jni :2j03h irpx1as5ing 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 a .oe633,ujpvuan: ntqnh.ux 0nd a mass of 0.20 kg is released from rest and allowed to roll down an inclined plane. How fast is it moving after dropping a vertical distance of 3au,.e6:.u 3x nuj ptv0hnq3no.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 ane8b)djcahrgww 8 7: b)d radius 15 cm rolls without slipping down a 35e incline that is 7.0 m long. Assume it started from rest. The mome 8b )w:eahj7wbg8 )dcrnt 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 momk8dayt3r/ k6xsr4f /.tsse -sentum changes 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#

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An ice skater has a moment of inertia oswk a+2*qw cng/mto.0f $5.0 \; kgm^{2}$ 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 at 5.00 rad/s with arms h-q)4k iqqx)textended has a moment of inerti4-x) qk q)tqhia 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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