95.02: An object shown in the accompanying figxjdjij6i hb60 0ze)d(q +vc;yure moves in uniform circular motion. Which arrow best depicts the nbc0e6j+;yv d hdz(0i )iqxjj 6et force acting on the object at the instant shown?

  05.31: A child is belted i8wk1lu42vs8vd6 m r6hjyxol*nto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exe84xd* smuj86lwly1vk h6o2v rrted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant spay/ x1zugpyz+v-e-/r e ouf/4eed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q. Poin z/4yoeyu -uz-fv/x+ge1rp/at Q is exactly half-way around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves in a circular path at constant9vdo * sc-:xs 4sj*n mb)hxw;n speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path fromvsw4nx;s-o:bs*cdj m )xn 9*h point P to point Q. Point Q is exactly half-way around the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constantf ;x6nci4)d aq speed around the vertical circle shown. Which arrow best indica qi )c6dfa;nx4tes 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 of a strb u*y3v0 hiv87tqehvcn,al5; ing counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from above the twirling mass. If the girl needs thni370;vvhl h5ye, b *8cquavte 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 a horseshoe-shaped path as shown wt eku+0nf6ru se:) +kjith the ars0fej6 nk+:+ek u)turrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on thi +g:c/au 694hlb:6hgc jfmqu e Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagrahu6lqug9f::+c4m ai ghj b 6/cm 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 object rests 2.0m frofpts)3xqfh ne4o, ;gl6b o+-um the center of a rough turntable as the turntable rotates. The period of the tu )+h l-x gsf; q3pono4eb6tu,frntable's rotation is 5.0 seconds. The coefficient of kinetic friction between the 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 nec)pos j9k 3onmf/1 uwsv6o /(feessary to keep a 1. 0 kg puck moving in a circle of radi/ 3v 6p ojo1ukfse (nsow/)9mfus 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on the *1oju 0(dm*wcju xs /lend of an 80-cm string rotating c1ojs* j*dlux0( m/u wat a constant rate of 4 times a second?

  09.24: A point mass moves a3*jaqza 5ek7 x1ila/h/l (1yfr u nnj2i; i5kvlong a horizontal circular path of radius 0.8m with a constant kinetic energy of 128Jev x l 5laj ;/2aiu1z n*kr1i fjnq/i7(a3h5ky. What is the magnitude 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 whirled in a horizl e5 i:mo3 z,vkrj,z,qontal circle at a constant speed of 6.0 :,ml5qoze,z v j3rki,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 roy/g8lehut)p xt 9 0iw ee0(3btpe, in a uniform circular motion.3 phtg8(b eyt 90xew)t0u/li e Which of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft .obxz*cp+sxy ml21k 1 attaches a mass m to a string and whirls it around in uniform circular moti.xx yk+2c zpbo ls*11mon. The radius 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 outward until the string of length L to whicxwww+o v1m01q bb zy 3mp:* 8r*xx8vmph it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circular arc. What is the tens my:8p x*v1 w0bwxw3+r1m pmoq*v8z xbion in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly 2 e)oo. zs1qzhh72bb f5 t3qttterrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hill s5f2 .bth zo)oh21qt37tbqezs have radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at).i-/79msnqkr dm + ojj 8ydmg a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be approximated as a circle7+/d9 )kqgrd.y-jmno8 m mijs 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 ikkm .aav4*s (ln a vertical circle at constant speed. The magnitude of kv(ka*.am 4 slthe net force on the sphere

  11.47: A simple pendulum of length Lhase0n*;92 1 rhy ddoaltb3l8hyn3:fjp ca point mass M released 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 bydpynd803 hjyt:arhbl; o cn3 elf 921* the earth, and F represent the 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 7c6so 3c 9pfk, i4w/oqge7ndjsimple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the 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 poin749ojoi7d ,6 snkgcwp/qc3ef t?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper moving 6z5i5jw otad3vqa0 smoad*)3at a constant speed in a ho3v06aa5s5ow*mda) ojq3tz di rizontal circle. If the same force is applied, but the radius is made smaller, 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 x 3 8eefc6j6r v4q5ngb8 ;ott ibif;u(to an ideal horizontal spring 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 b;;jx3uc fe(r85 6itoeibvgn8 fbq6t 4y the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass withi,gi jvnsvfuw w5.p qy7p dt7*)e0* 9u a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force,ivsp*qj7p7 igf 5u0wu*)w t9 vn.yde acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coi( zi y0sc; :*kgtyvgu0ns (labeled 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 coins from the center of disk is0: g0y*kgtzyuc s;i( v 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 end of string and moves about the stya(k;dagj :hqp62s6 d:7 lngoring’s fixed end in a conical motion with a constant speed of 4.0 m/s. The(n6qg;yg p jh7ksodda62 :a:l string 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 as shown in the figure. i3w)(j: fwn4ky3 qsf aThe string to which the mass is attached has a length of L = 3.00 m kjf4iafnw3w:y 3(qs) 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 j(b(r3/u:hdpycc e8 (k :hreirest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its(ckuep3berrc 8i hh:(y :(j/ d center with 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-lgk1h he t;d52hv os0 a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from r1;ghhs-dk5v 20otehl est 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 +*8(7s lad vtm/hdpr.kwc* d ur pg/)ptop, with initial speed 17.0 m/s. The object’s speed increaswlpk*p )*.v/rduc8d sm+/pd r7th(ages uniformly until it has moved counterclockwise through an angle 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 top9+(3 rmyawgfq , with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle( fygmr3+q9a w 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 block rests at the bottom of a bucket mbxbfr* f+9:yadf *noj(37nk. 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 jd fj(y xbk9rab+ m:nff*o 7n*3ust fast enough for the block to remain in place 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.