95.02: An object shown u5fuy6bae kk4apd4 78bd.dl4in the accompanying figure moves in uniform circular motion. Which arrow best depictuk.l d4pb8fk45b76 audye da4 s the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotate63 gdgva/v :aery5k*ls counterclockwise at constan35edaay :6 vgk *glrv/t speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuou)ci fvzo4urygy* -y,,sly moves in a circular path at constant speed in a counter- clockwise direction. Consider a time intezi c,fy*,)rvo -4yuygrval 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 m s;5z3x s;w eqno5ol7voves 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 from point P to point Q. Poinsxz5sw;l7qeovo n ; 35t 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 e/n ra l 73:rt9warw+e4/bbwaconstant speed around the vertical circle shown. Which arrow best indiclawbwr7/3e:r/a e9 a r4ntwb+ ates 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 string counte wla+j:vnm2o:rclockwise 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 s2w+m: lo:nav jhould she let go of the string?

  15.23: A car moves wyon f5e82)n1cwvlk 1aith constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of th2ykfew1n)1lvoa c85n e following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on rk zm d(tstp.+09-dxu the Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At tt90-+tdxzkdm (ps r.u he 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.r/,n+;aj (4id xe gq xzkvd0q/ kf5h6q0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5dx(+4kji /hnkza /qvxq6rdq ;50g,ef .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 necessary to keep a 1. hjsie;l5jpg5w5cd0v;3q ) n ;d l(c6 /wv bdmd0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a spedbv5nc5cj3 ;lw ds;0h im 5jd6lwdeg/;p)v(q ed of 2.0 m/s?

  05.03: What is the centripetal acceley nz +dqv(ov--920kxgyyw ) )qq dh(amration of an object (mass = 50 g) on the end of an 80-cm(q +an)y2h0(9 d)-v vxgzqo yqw-kydm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves alqg. i+geu(eof.+kw )nong a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the m .kn(w+g)eq .feu goi+ass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirlcqnnee;ku+ 53ed in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work 3 cu5;kqeen +ndone on the ball during each revolution is:

  99.22: A child whirls a balln+u)h1z cp kxv/w;h(v 0k b6pz at the end of a rope, in a uniform circular motion. Which of pwh1nv / xp)kc6b;z(0z kuvh+the following statements is NOT true?

  00.19: An astronaut in an orbiaxd5 4 jm;lmozjc* ,3wting space craft attaches a mass m to a string and whirls it around in uniform circular moja5mzw*ljc 4 d;om, 3xtion. 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 np+3m f:xll*p:4wjof 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 tensi3onflj4w: pl : xpf+m*on in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrli/+ak 3ni zi 2pin6mzm0, y.bain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills havknz/m2 a,m.ip+l6zn3iyib 0i e 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 speedte s) sfc/kbf2j.p-/be g:s i* of 12.0 m/s. At the very top of the hill, the shape of the roa: 2bekt.fcif/bs /*gs- ps e)jd 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 movivj4 s 2)c)1d fnazcy7xng in a vertical circle at constant speed. The magnitude of the nzs4 j)ca)yxvf2c17d net force on the sphere

  11.47: A simple pendulum lzxr) dy.,c 6yof length Lhasa 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 magnit)z lryx.dcy6,ude of the gravitational force acting 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 connected8p.*hb3f3 ,*z osblpkxw oqx 6 to a string forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the zx3p*h*qfwk 8ol, .osp xbb36tension 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 n180o -p,kiavad zw0nwewtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what ha ovk0z0w,a dpiwn81a- ppens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, cony ikjjlzp.9d;4siz 32nected 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 fyz;2l.i d skp9j3 4jzirom 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(xptdy1; 0e b yecw obsenf,e/ (f00o:.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowes0p :yteo 0ce oy(;fbf sx0e(wb/1de, nt point of the circle?

  14.23:Two small ident7x w bxeu)r/c9d rym;+ eva2h8ical coins (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 is ;euy v)+crxd9a2 mxbe/h r7w8related 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 cvu. m3rrk3(d vonnected to the end of string and moves about the string’s f.3r d3v(rm ukvixed end in a conical motion with a constant speed of 4.0 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 circular motion as shown in the figurt juqqf.qof06y2d4:t xf0 3jye. The string to which the mass is attached has a length u d 304qfqf0yf2x.jj:6ttoq yof 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 e ,r/clls *ap66n2e g2m y7nab, bpyuyyt;s;8mass 11.0g is at rest 30.0 cm from a horizontal disk’s center. 67eynbppcy ya* mus/, ;y snre8,g ;226t lalbThe disk starts to rotate 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 mass M = 2.0 kg is cfdza4 +8p 4m kv5a,yiattached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant dpy4+5 4z8 c,vki maafangular 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,(weu9xfx / sb6 with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countere9(fx6/usbwx clockwise 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 speeh)twgwnl:k,m6,6oc k )e1o yz rh;ll;d 17.0 m/s. The object’s speed increases unif1t g6hzww6,l,nykc; hlo)mle; o kr ):ormly 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 time for this motion?

  17.38: A small 2.0 kg block resti58vop,mv9 e gs at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bm ,v8vi59eogpucket reaches the highest point in its motion, it moves just 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.