95.02: An object shown in the accompanying figure moves in unifo4l :6i(ay08 x l hyyrxzne:zh3wr6.uurm circular motiorx hz:i6(uwyh 340xr6l.:8yezu y nlan. Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotgz8 ur5q.gv0tates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exegugz5.r8 qv0t rted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant g/wyy9 t7l3ofspeed in a counter- clockwise direction. 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 7yfy3w g9l/tothe circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle cog3rravz6t;:rczh5 w.ntinuously moves in a circular path at constant speed in a counter- clockwise directizr vczr 6.t;3g a:h5wron. 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed around the vertical+spfxh,)5cas )c5 boz circle shown. Which arrow best indicates the direction ofcp )ca+)5ofss x5,hzb the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end 7v-jj 3tv) gpfof a string counterclockwise in a horizontgvf 7p)3jv- jtal 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 go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path a 2phhzh..i,rf(b nk(t d9c b0cs shown with the arrhfb.c h.( dn r,9(tz0ckh2ibpows 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 experiment wi7:xi:a.fzm q ith a simple pendulum that is released from the hori afqizi:m x:.7zontal 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 of(o5mskqczd v4os: ar/iqc9) 4 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 coefficient of static friction is 0.80. What is the magnitude of the force of friction acting on the object)dmqkv:s 4(zcsc5 o /94aiorq ?

  07.19: What net force is necessary to keep a -/6au7lfwg8g2wzb8djr0t6 fxx p ip 41. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a s-xd zf/f4j 20ixu w6 abprg68g8p twl7peed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an obj o/xmq14 nlcs*r*zrn l3:lc3uh/l 6b ject (mass = 50 g) on the end of an 80-cm string rotating at a csc 3u:rh c olmjn4*//nl zbqxl3r6l1*onstant rate of 4 times a second?

  09.24: A point mass moves along a horizontav vam3c:qvdc:xtrvu n ;l j-64f+9sq5l circular path of radius 0.8m with a con65n:x fa: ; qv3jm4dvcv+ t9c-urqlvsstant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached0gg)upbg9j 2 5 2cfxl 7cacmq3 to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. Sex )0gc5g2jc7ulp mfqb3 a29cg e figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a u3a.l5 c(qntr ball at the end of a rope, in a uniform circular motion. Which nac( l.rt3uq5 of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a string7y-qiqx -hp4 s and whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass is ix-q74hp-sq y 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 which i b( +zjdy(8gwht is attached makes a 90- degree angl(yd 8z+ hbgwj(e 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?

  94.15: A car is traveling on a road in *z xi7jx7;jz4 bqj7dy hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms oz ;z*bi7djxyj 47j7xq f 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 ajd quxx+:(,gzt a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be apug,jz x+:qd (xproximated 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 moving in a vertical circle at constant speed. Thkkzo *: 9,akfye magnitude of the n kf9k a*zk:o,yet force on the sphere

  11.47: A simple pendulum of length Lhasl91qayq 0*(sw porc n7a 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 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 atol9 a0 r17q (nc*sywqp the bottom of the arc (point P)?

  16.32: A mass connected to nbg. qu0l 41 kjcv3*9 taebihw5o- l4da 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 tension in the string (T), the gravitatiwa3*i.v0e u jl1d9h gb54 n-bc4lotkqonal 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 q8 m ;vhj1vm8xnewtons is applied to a rubber stopper moving at a constant speed in a x;vqhv18j8 mmhorizontal 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 atluwy.; ts14ea2 r8/z sfyuo6r rest 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 appyusuwts; 8la1r oe. y4rzf6/2lying 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 mass with a cl/lfiwq dh-;0ha) t/ sonstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 ms/hwdh0 fq)ta /l;l i-. 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) ndenr ,8st4oc9 5 d;nware at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its cent8d o 5wcdr, 49nn;senter. 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 movess whl1jj. o/h9 about the string’shw/h l j9so.1j fixed 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 cioh: yz9z;2n nfs s(me2rcular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of he( ynn 9 zsm2zo2:fs; $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is at rest 30.0 cm from a h06mq p(c)jsq yorizontal disk’s center. The disjqp0( 6qsym c)k 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 7.xn g nsweb5sq4k42y ,mv.zskg is attached 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 angu 5y.wb 2k4z n4x nsqs.gvsme7,lar 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 circlaleu6hvk*ii9j/;.8gh :y r0b j t1vane, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformlygvh j8at:h j69rb*k.uvl;i1i ya/n e 0 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, starti9ovd7nt(m2g-z d2nl fng at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it o n-(v2g9zdtfn7 l2md 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 tc*. u;hars6gq he 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. When tur;6gh* a.cs qhe 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.