95.02: An object shown in the accompanying figure moves in uniform circular m /po.pfq2o. ehg wpc:a)6 4iqrotion. Which arrow 6g./qep) hcirpf4:2o aop wq. best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheelots-qz,w o. 7r seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which .,7zs- wrotoqdirection best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular pyn )v y1pm2,0w yuym4lath at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q. Point Q is exactly half-way around the circle from Point)ulwn1 my v y,pmyy420 P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves in a circular path f.v,kl2 ufaop48xccwt *-p9d at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q. Point Q is exactly half-way around tcd.tavppc u8xl, k2*w f49-ofhe circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwisep sm19 wl+.gfx with constant speed around the vertical circle shl+f.1 9 xpwsgmown. Which arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end o, ,t0smri9 o fz9fpudkit l-zf0g16* wf a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from above the twirli0-*fs9z6zoi0p,t9 fduw,r kg1 fmli tng mass. If the girl needs the mass to pass through the point labeled P in the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves with constant speed around uu7 y-v,jhgg2 a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleratiu hv2g -jyug7,on of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an osut6bg.y i8k7kz+a :experiment with a simple pendulum that i8o +7yig k bk:.zsa6tus released from the horizontal position at rest. At the moment shown in the diagram with $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-like ob+yzyt4(qxu p-ject rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coefficient of kinetic friction between the+4-x(yuqy ztp object and turntable is 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving in a circ. w8wxnz4tbs-le of radius 0.5 m on a horizontal frictionless surf tww8.sbnz4 x-ace with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on thz utk4cpd)p86 e end of an 80-cm string rotating at a constant rate of 4 timep84ptud kc6) zs a second?

  09.24: A point mass moves along a horizontal citx(g-g aoi0afg m87r+ rcular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnit0(atf 8+igg-x a7mgr oude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whiru bu)j3l5vcgkhh /b+,lr;dg-f vgm,r v9 6 6tkled in a horizontal cicbur j f 5+gv6h g/-lr6)mt b; ,kh3ukgv9,ldvrcle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unifoeqdx i njas.ty :+3,b(rm circular motion. Which of the following statements is NOT trun3,+ j:(ae.dysib qtx e?

  00.19: An astronaut in an orbiting space craft attaches a majo0vw+je 8u)notmsrm3ng 7mt74 s 57bss m to a string and whirls it around in uniform circular motion. The m g 7b38)os7 tvnwrmj seuo5nt07+j4mradius of the circle is r, the speed of the mass is v, and the tension in the string is F. If the mass, radius, and speed were all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outwartwg-r 9 pp6-c 9-parvad until the string of length L to which it is att--gp vrc 6w99pt-a rapached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circular arc. What is the tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling ovuw),,kc- qzy+ kw vq)n a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have ,yc vkw,)zwqquk -v+) radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves ove psc 28b4q.2o e8zfv: +*ri-qxuzpjokr a hill at a constant speed of 12.0 m/s. At the very top of thksr2q8-jopcqv iupz4:obz* .e 2+xf8 e hill, the shape of the road can be approximated as a circle with radius 25 m, as indicated in the figure. Which one of the following choices best represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in uhu;fo;9uw 4y wml;n/a vertical circle at constant speed. The magniy;;wl u 4/u; owhmu9fntude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releascbxct (;hm)5p ed from rest from the horizontal position shown. In the absence of air resistance and friction, the mass swings through the arc of a circle. Let T represent the magnitude of the force from the string on the mass (tension), G represent the magnitude of the gravitational force acting on the mass by the earth, and F represent thec( ;px5 tcmhb) magnitude of the net force acting on the mass. Which one of the following choices describes the relationship among these forces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a (xo n2ebhd( a7gv+k1a.sv 6vw simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of t v.vwhbdv(o6gsa(e2n xa1 + k7he tension in the string (T), the gravitational force on the mass (W), and the net force acting on the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper y2)ot55 m*be or+7g5kv kkbi6 jyvsw7 moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made sskt)7bywre7 k k5bvy 6v5g*+ mo52ijomaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an ideal h mn-b zne(s0gpn 5j+(/hj9m18 nwvkbporizontal spr0p8vb jebsnnh/gn + 1zmj -(kmwn95(ping that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at this location by applying a 10 N force. The spring is brought back to equilibrium and the mass connected to it is now doubled to 2M. If the spring is extended back 30 cm from equilibrium, what is the necessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a (jmw0e,p. .j +-xro8u y w6ui s,arvefconstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass vojua,ms0. 8(ryi6re-w +f x uewp.j, when it is at the lowest point of the circle?

  14.23:Two small identical coins (lax ta8) jrkj+i(beled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coi) (tj+jk ri8xans from the center of disk is related by $d_x=\frac{1}{2}d_x$. Which one of the following choices correctly identifies the relationship between $f_x$and $f_y$ , the frictional force on coin X and on coin Y, respectively?

  15.40: A 2.0 kg mass is connected to the ends)avghlk c:0 3zw5wolf w88-r of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string0o8 zl- cawwwg:)h5 3 vskrfl8 has a length of 2.50 m and forms an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform circular motion a 0ch9xyd9e +fis shown in the figure. The string to which the mass is attached has a l9e9cxhfi+y 0dength of L = 3.00 m and forms an angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is at r2u 64id8csdgnpxq9 khv4c:a7 est 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center wi h4 :iqnsxcdc74dp2gu6 8k9avth a constant angular acceleration of $4.50 rad/s^{2}$ . What is the magnitude of the net force acting on the object after a time of t=1/3 s if the object remains at rest with respect to the disk?

  10.35 A point object with mass M = 2.0 kg is attached a dtu +w-8vty+ ru8v. c5 paq6g66wjujqiistance R =1.75 m from the fixed center of a disk as shown jg 5v68. rc-qpj6+aiw u8u+vt uwqt 6yin the figure. The disk starts rotating from rest with constant angular acceleration $α =5.00 rad/s^{2}$ about an axis perpendicular to the plane of the page through the disk’s center. After how much time (in seconds) is the tangential component of the point object’s acceleration equal in magnitude to the centripetal component of the point object’s acceleration?

  16.39: An object moves in a circle, starting at the top, with initial speed .kg2t ipq27ofbjw:;ox2q lp(17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an an2f 2;(ko .pjqpti7:g2lqb wo xgle of$55^{\circ}$. The average acceleration for this motion is $9.8 m/s^{2}$directed straight downward.
What is the final speed of the object?

  16.40: An object moves in a circle, starting at the top, with initial spe* zd2-fwc zh9x:s 44ncjxr10kx4 lbzbed 17.0 m/s. The object’s speed increases uniformly until it has moved counterc4sk: b4h*rzzcx2dxbx zcn4 -j19l 0 fwlockwise through an angle of$55^{\circ}$. The average acceleration for this motion is $9.8 m/s^{2}$directed straight downward.
What is the time for this motion?

  17.38: A small 2.0 kg blocke /ok19acbxz8k-fnc7 w 0wfj 2 rests at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fast enough for the block to remain in pkc 8o 27cwex- /wkbf0j19zfanlace in the bucket. When the bucket is at an angle $θ=30^{\circ}$from the vertical, as seen in the figure, what is the magnitude of the normal force (perpendicular to the surface) provided by the bucket onto the block? Note that the direction of the gravitational field is indicated in the diagram byand that the block does not touch any sides of the bucket aside from the bottom of it.