95.02: An object shown in the accompanying figure moves in uniform circula(o7exev/wa-k r motion. Which arrow best depicts the net force acting on the object at the instant shown?7-ov ew(/ exka

  05.31: A child is belted into a Ferris Wheel kmf *86nunx7rseat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which directi 7nx*6u rk8nfmon best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuousza0ew4emt1v- v +8oftly moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along thisoemte 1twv-48a0 fv+z 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 ius +(h:w rd :u wf04uy8bhx8 drtx-s(vn a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this cxu:u84(r :dxv-h+hd0y sufb8r (tswwircular 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 ht6 kg3-nd8+kxrsr y5the vertical circle shown. Which arrow best indicates the direction of the objec 8grk6+nhk3-ysd5 trx t’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a stsa)hvw0+ :kt lring 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 nees0l:)+ hkawtvds 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 79tcgkfu. 4 ndm:2uw karound a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in:kudu4ct 2m.k 79fgwn traveling from Wto X?

  08.35: Astronauts on the Moon perform an experimene+tckl oig, 5* wv,hs8t with a simple pendulum that is release5 il eo8,sctw,gk hv+*d 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 obg do q/l(lq+yhje o6q 9bgv+.1ject rests 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 coq(v61d .o+e9l hogg+ qy bljq/efficient 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 moving in aw9;ry;1m98bnlurr9a: l hcqkyv b)z1 circle of radius 0.5 m on a horizontal frictionless surface with a s:q)r cw1brz9vl 9kaumnr;l;yhby981 peed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = o c1ifm;oe r),gxr.ysa*c )m/50 g) on the end of an 80-cm string rotating at a constant rate so x1,/ frc)m;o)a*mg iyec.rof 4 times a second?

  09.24: A point mass moves along a horizontal cqv*u0j tm jz)i h4s,9bircular path of radius 0.8m with a co0q b9j*,vhz j)iu tm4snstant 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 attached to a 0.80 m striy i4+u0mox/ znng and whirled in a horizontal circle at u +xm/iozy40na constant 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 motiqq,c:h0fjcsk1cx 5ws 5 2af- uon. Which of the following sta qh0 uw52f ,q:fsacs5x-cck1jtements is NOT true?

  00.19: An astronaut in z h7a/ude .-jwan orbiting space craft 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 weudh7-/a zj .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 lengthgua e sr ; up6l10u6xw;c8u,wl*fe,ij L to which it is attached makes a 90- degree angle with the vertical. The mass isewejs, p1cu;urfl,lag0*u6i8;wu 6x 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 roahkub- v..9ec; 4rf dkcd in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The dri94fk er-.bcudvh; c k.ver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill a/-9vhbn z/ve0s z2 jqlt a constant 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 represenq 9bv zz2h/ln-e/j 0svts 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. The)r; dq(pe 7wi6r,skd c magnitude of the w s;ricrkqd )d6pe(7,net force on the sphere

  11.47: A simple pendulum6 ve8;x *wm; vk*shystt+i v,n of 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 magnitude of the gravitational force acting on the vmx8whvit*vt s; ;n* e y6,sk+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 simple pe+f,:8 rjltgnendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the 8+g: ,jtlfe nrtension 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 5.7;dh x+ dpynb20 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the px+;d2db nhy 7radius 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 frictionless surface, connge og-((yt ,nlected 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 from equili-l(,ngey (gto brium, 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 wf4chugz l)cwxr+ 28gnd a97s (3xx 6gzith a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net f7n fgx sg4 dg9zc()+h3r 2 uxl8zaw6cxorce 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 h5kjybn wfbic;e1q8 l4u1c 2jre5 6 *pzorizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. Theb uilr zfj1pn5 ejykc46c1e2;w *b85q 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 the slm-fl5/ xwib9xb6 -6tgk2zp had* 7lhtring’s 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 x t5 kl9mpg*l 6if7d b6zxhah-/bl-2wan 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 figul;;* gmrk58*paqpyx kre. The string to which the mass y kpa;;*p5xrq8mgl* kis attached has a length 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 o+-w x(eyvr-l- 4thmoof mass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The diskmwxyht(le-r4o + vo-- 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 maaa 6spvdn*6 8 4in9podss 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 rotating from rest with constant angular acci 6 6nsva9*pdp8aon4deleration $α =5.00 rad/s^{2}$ 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, wixlxlsr8 9/p*p1gecc( w+7 vm5rx.ivoth initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved count.oe+7pcx ll1xr8*s rm cgv/ivw5 (p9xerclockwise 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 qe :m+kh9 8i 6di)l5i jlvhl(+rg- hyycircle, starting at the top, with initial speed 17.0 m/d m ehk(ijri5+ ly 9v6qh8)+:gllh-iys. The object’s speed increases uniformly 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 rests at the bottom of a bucket. The bucket i zc (rkp wvc4c;viz 1c71*kof.s 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 the buckezz7(ro*. fc1kkc;pci cv 41 vwt 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.