95.02: An object shown in t3nm qq7mse ;d3- 0ckc,0osgo ahe accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the objectmac;n q0qo 73o c0gse-m3sd,k at the instant shown?

  05.31: A child is belted into g1i3+*jcp)el:iy2 fn6 mh pxt 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 6yc f*petgj)2i :lhn+pix1m 3exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular par( x;hpm3n a-jth at constant speed in a counter- clockwise direction. Consider a time interval during which the particl j(3x-m pranh;e 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 6kylwwth;1: z moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path w :;lkwtzy61h 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 clockwise with constant speed around thfgad8yj 18o)wm of :ju5qk6l0e vertical circle shown. Which arrow best indicates the direction of the object8ka8jfwd 5o0l g qu )f1o:y6jm’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass qxc*jw 5y8urijxsvb.f)d.l q0 (o05c connected to the end of a 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 let grdwqjbos 0ij*q c xc5 v. l.0)(fyu8x5o of the string?

  15.23: A car moves with co no xo9+vokw rgsy- 60pvu1qo8o4 us8 ht)vp1+nstant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following+oup o9s6h vvorn+oxtq 0-og14psk1wv)u8 y8 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 experiment wiqot. rk7/ may;th a simple pendulum that is relea qty.7or/;ak msed 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 object rests 2.0m from the center us h9wtn)bvry50v69w of a rough turntable as the vw)6h 5u by nr90twv9sturntable rotates. The period of the turntable'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 necesshab1w fx5 z-(sary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizons1h5 -axb(w zftal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of av3 cyn pbyj9+oecm/ oa2 p)t16n object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 )pyoa6o nm1et+3 2 cv/pjycb9 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m witha c+1ge6 scw uqe5u(f7 lla5w) a constant kinetic energy of 128J. What is the magnitude of the net force acting on the cwa )w5s+l17q c aeg5u uel6f(mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizon16 ehkl1*uj ygab:5 e/rj-oo4a:m i nntal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the bknalmu1i : 5nebjg :/4y-a*6 hrjoeo1 all during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circ ;nvqlz)gj ti6(6bdok,y s1:hpqm;s2ular motion. Which of the following stat)kn qs ijg(b;,sh;z lmvdqyt21p6 :o6 ements is NOT true?

  00.19: An astronaut in an orbiting space cra9bjov8 k.;-lh tkgsd)ft 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, radius, and speed were all j dv9otgs-l); .kkb8h to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outwardg4kj .mw 8vvgqm0pz;smmh *-4rub/ b0 until the string of length 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 swings through the bottom ofthe arc?gr0/ m-vm44m8.m;bwu0v s*bzp hk gj q

  94.15: A car is traveling on a road in hii.z6.7on dwts lly terrain, see figure to the right. Assume the car has spe67dn i.zw.ost ed v and the tops and bottoms of the 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 of 12.0 m/s. A j ow9uy(i :t5pa(*gevc mbp3*t the very top of the hill, the shape of the road can be approximated as a circle with radius 25 m, as indicated in a5g pt wyev3m o*:*ij9c(b(up 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 -b 3s dg8y(iglis moving in a vertical circle at constant speed. The magnit (d-s8ibg3 glyude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M7iqb p8 rsea;qv5bi2jnj 0/q3 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 actip37jieri/5j s ban;0vb2q8q q ng on the mass by 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 s,7vwu u*hpa8cimple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the 8pcauwv,uh 7* 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 point?

  04.41: A centripetal force of 5.0 newtons i3cxwt bdi 7/;j1jo0 yfhw4/jrs applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force isjj/ f7 w ;tcboih /3j4d10ryxw 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 onwga d z658dofz8t)5vx0e,cuz 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 doubledg u8x5aof6dz, zzt0 )wcve58d 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 constant speed of 3.+l6xgb ukmhg fo17-5 a24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass whex-abl f g6u7+ 5om1hkgn it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X ajmy/ kd/-qg/ sndY) are at reston a horizontal disk rotating at a constant rate abo s/md/kjy-q/gut 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 th . a.fnfa(bbbr as3:s*v9 )kube string’s fixed end in a conical motion with a constant speed of 4.0 au b .sbb.fk(an*)r s:3vaf9b m/s. The 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 circulac*dhv 6lv tojdz/39 9fu fyg74r motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms a/36yogl ch vu94j9 t7df* zvdfn angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.7zs6ossu 0t, 0ir mkt40g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular accelerationk0rt,t7ius o6s0 z 4ms 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 di *f+a7ltr(nb;kvb i k1stance R =1.75 m from the fixed center of a disk as s; l7*kb1 (kivr+atnbf hown in 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 speedok 7*e -hpin-q 17.0 m/s. The object’s speed increases uniformly until it has moved counter-* ehp knoiq-7clockwise 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 top, with initial speed 5slw ++pf1b,whit(n:bv- fjx f8ck b;17.0 m/s. The object’s speed increases uniformly until itw(n :sx5;hbk f8b ijlc w,ftfp v-b++1 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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a btin (q6fxhlvp6k79 )p,m mkz:gmj3) f ucket. 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 remxgnmv l:q k 96,7i6(hpfp)z3fk mm)j tain 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.