95.02: An object shown in the accompanying figure movc*v4m vz: 8ykrcgtt* /a-m+wq rm4wku;8e8o m es in uniform circular motion. Which arrow best depicts the net force acting on the : -cacgkvtv* m+48myo/umzq8 wew8r4m trk; * object at the instant shown?

  05.31: A child is belted into a x1i gb((.+ 3bb lp7y; emlpakbFerris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best repb.belbx7abi g; kp m(1yl3+p( resents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously ph6q ,-urdd.f3enu 4w moves in a circular path at constant speed in a counter- clockwise direction. Co,6.wdfedu rh34n p-uq nsider 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 at constant speed in axv:cr+ *ndom9d2 +ja)mdk 8 vr counter- clockwise direction. Consider a time interval during whicx+2 m aor r8:9)d +mdvkj*dcnvh 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed arolja.p ;d2no0c9cd2iy)i 5x o pund the vertical circle shown. Which d.;py5ix i2dc9c oa)lp n0j o2arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small l.(s n 2q6drqpo9v0eamass 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. r enq(l0 ap.s6q ov29dIf 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 a horseshoe-shaped path as shown wcpr6.vxj b5kj7 *a xt5ith cbxj.r 67x t *j5k5avpthe arrows 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 the Moon perform an experw*t unpho s6:vr( )0caiment with a simple pendulum that is released from the horizontal posi p*w0)6ao:r vhn(sutction 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;ov)bxkh m3n r 7mub-1 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 object and turntable is 0.50, while the coeffv -ubn ;3mxb71mr hok)icient 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 movingxhv6g cs4)q3 :elsbdjs5y 5q 1 in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s1:jl sd x6hsc )yes545qgb qv3?

  05.03: What is the centripetal acceleryxw3 ;mr9k,u4oo*g4k hr8r eration of an object (mass = 50 g) on the end of an 80h8or4kekr w9xguy3omr,*;r 4 -cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m pyoqj/ke;mk7 pl6cf l4::/c:nsn o 4jwith a constant kinetic energy of 128J. What is the mae4j6k7ln:j ckn: qys/p:coo plm/4; fgnitude 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 whirle3 vz(gi*b1) ,ur3+je 1s pvjn ,ajrt+zs zzkc/d in a horizontal circle at a constant speed of 6.0 m/s. See figure 3zjrzr v(bsju3kz ,c* a /++vp)setinj g1z ,1to 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 abg+2c qcmii7 5ab1 vsp;v6 0 jc9ff7ti uniform circular motion. Which of the followinqp7i7 cbfc5 t62f; a+vji1ivmg b09s cg statements is NOT true?

  00.19: An astronaut in an orbiting space crafr 1scq/3*iueqt attaches a mass m to a string and whirls it around in uniform circular motion. The radius icuq q/3sr*1e 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 m/m6xhe)chmx 87jp ,h 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 t/68mmj hhm he7 pcx)x,he tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrd 9x/k 2tpwfeg 5xfp0;z/ct.oain, see figure to the right. Assume /tx x gzwfp2fd0 tp/ e9.5k;cothe car has speed 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 co4mek)kw qds8 x1wubup: 9e*. anstant speed of 12.0 m/s. At the very top 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?w xe.1 ma4u*b9d8 ukk:e )psqw

  97.13: A small sphere is mo abobp 6rg)m5;pa2a17tfuy a *ul/ 5hjving in a vertical circle at constant speed. The magnitud7h)m5; t 2br6agaafpoab 1y u5j/ulp*e of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest from th3lvnenb)*o4 ue horizontal position shown. In the absence o)vlo 4*3nuenbf 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 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 foani/4axiohj3ajb4d pw wc wz (k0++., g3-a ocrms 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 tension in the string (T), the gravitational c4bh0 w 3j/oaipowai jzc,naxk-w3a(+ . +g 4dforce 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 movize ovd,1 (d1x u6rs;o4 mw*b:wj(kxghng at a constant speed in a hor1j*1w(o ok (h;zd x: ,mvdux6wr4 ebsgizontal 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 frictionlessnn6 y s6/ xrgzux f/2z*nl01wk 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 apps6xn//wn6 21zlkrn xgz uy0*flying 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 mass7 j2l +sw6.mbxtzx4ut with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the ne+ x7smuzb .w2t4l 6txjt 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 xkkihqs9msq8 1 y23w( 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 related bky x8kq (s w9hqs12i3my $d_x=\frac{1}{2}d_x$. 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 smzu u ,nc57vn;tring’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has m; 5c7n,uznuv 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 nv3/. s5 ri/o1 rjucsffigure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle 5 rsiu.3o1cvfjn//rs of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of may(ex s,r vx)t,0/p ibsss 11.0g 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 acceler 0syspbxi,,r()x/v etation 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 w*nb z3ka +hq*is attached a distance R =1.75 m from the fixed center of a disk asakbw**h z+qn3 shown 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 a36eg y ihvg.7j circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwisi j6 gy.v3eg7he 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 jol z0x90jas3initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countjj oxl0s39za0 erclockwise 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 rlm7co (;dpl 4:q kpk1j8lkwq)ests at the bottom of a bucket. The bucket is spun in a verticadp l7:kqcko 8qlpm1l)k ;w(4 jl 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. 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.