95.02: An object shown in the 5lik.u ;px1/ 1blfqs 8e*rvb naccompanying figure moves in uniform circular motion. Which arrow best di1bupe v*s/8nlrklx5;f .bq1 epicts the net force acting on the object at the instant shown?

  05.31: A child is belted in21qophf nnk+jcaw7 f+:nc4:.nca ieg) y6bz*to a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direccj a*f7knah cp bnw1+.z2+qfyonn: gi)6:4 cetion best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constantx3;xg*) ;miz9z r lfvk speed in a counter- clockwise direcmzf; )39 lrvki; x*gxztion. 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 P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves in a circular path ajbpfn, o7.1 3 szc8reqv;:m mhr:hi r*t constant speed in a counter- clockwise direction. Consider a time interval during which the part:;ir rpjs b7m1:*cqh.,r3ohvzfn8m eicle moves along this circular path from 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 cl m8/rghcd-d0yockwise with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s instdrdm /hcg0y- 8antaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a6eu2c dsij -(14ia*kb-wp2an n;be im string 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 the mass to pass through the point labeled P in the figure, at which lettered point on the path should she let6 b4iap-mud2iew-i bsjk a(ec;*2n n1 go of the string?

  15.23: A car moves with7 g* t427sjwq gcxam9k constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one otkx*9w2sm7g 74qacg j f the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experime -1 hh*edaa6lovddi 4s7y4 z9rnt with a simple pendulum that is released from the horizontal position at rest. Ad*hlv1rdz 4a 4-o9aeid sh67yt 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 object restxazl nn3wgz;; *gna8i*-- jehs 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 fri-ia;8xzw* l neag gh*zn3j-n;ction 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 necessary texm za,com yqm3ae-*o1/ 2gz2o keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionlessoo qza3g2yxaz, -m m1e*m2c /e surface with a speed of 2.0 m/s?

  05.03: What is the centripeh; *)f2ycsw vm:.(olqy z9dhr tal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a)hhd9fv;.ys(cq ywor:*2 mlz second?

  09.24: A point mass moves along a horizog +3pl1f58g3d4 kxapii2kxfvntal circular path of radius 0.8m with a constant kinetic energy +lkx4p 8v g 13a idg3p5ixf2kfof 128J. 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 k vwij8vu.u*) and whirled in a horizontal circle at a conuvuw).*vk ji8stant 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 uniform circular mozalm)n h3i wk,01 lp0ption. Which of the following statements is NOT 13wa, h0lmp) lk p0niztrue?

  00.19: An astronaut in an orbiting space craftn9(jgl nr ,fpf54hk/ i attaches a mass m to a string and whirls it around in uniform circular motion. 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, ra,p 4/ rk5nn(fgjihf 9ldius, 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 len-ct jphqxns ab3 ;)geu;4+ xb,gth L to which 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 tension in the string when the mass swinb; e ux+t pc,4j3x)s;qagh-nbgs through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the rig)nw fp3bc -wn9x2a(xp ht. Assume the car has speed v and the tops and bottoms of thep2 pawxc3)9 (-bnwxnf hills 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 a constant speed xd*nbb;60xg *5kurl fhq+ih2 of 12.0 m/s. At the very *x6* qr0b5+glnhf 2d;xhiu b ktop of the 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 m py;buztf/35is moving in a vertical circle at constant speed. The magnitude of the 5p3uby ;/t zmfnet force on the sphere

  11.47: A simple pendulum of length Lhasa pointgn;b /q(jl,z+bool: *nrwu 0y 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 by the earth, and F represen(o lqj wo yl0b n,:bgz*+u;r/nt 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 simple pendulum. The ma lcrh q.g;28iass 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.;2lr8aq gi hc), 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 fok8+ aigl5w5ypcgt;w 9rce of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the r+;al g5598gwc k tywipadius is made smaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest7 a opgeep9u+0 on a frictionless surface, connected 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 exteae0u7+9egp po nded 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 constant speed of 3.x6 :riehw1 -aai)axp 124 m/s in a vertically-orientedpw1hai) : 6 axxeri-a1 circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal dm 4qnsod+;d72fq o+ff isk rotating at a constant rat;sd47dfq ofomn2 fq ++e about an axis perpendicular to the plane of the disk and through its center. The distance of the coins 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 end of string and moves about theu-h 8;rja u:ji/gz5as string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has-ai8z/;asj5u :g ujrh 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 5 dw(qhv p;0gijilh ; m60i-vuin the figure. The string to which the mass is attached has a len0vgw ;hlvi65hqu i;(ip -0md jgth 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 qy*8mgsw 0*xc, wytal-jly37of mass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to r,-0yy*sa*xw3j7 yc m8w gqlltotate from rest about its 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 massozkt5m ei(gmk fiz(; +c7x;m6 M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts r7kgozef5 6;ktmi c; x(mi z+m(otating 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 aopq bk,l0(no3bi0h *u circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle (0ouli*b 3opqh n, bk0of$55^{\circ}$. 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 thcv agj 5tl-9n.e top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thg-nl5a j.c v9trough 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 block reste kq)l11sw/wxjw8 iv,1ht) svs 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 place in the bucket.st1j khi,w8 wve l1 v)1/s)qxw 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.