97.01: A force F directed at wf0u t/ to8t(kerf+o, an angle of θ above the horizontal is used to pull a crate w r0tou k+et/t8 ff,(oa distance D across a level floor. The work done by the force F is

  97.33: A softball player cr *y+ ea6vubj-atches a ball of mass m, which is moving toward her with horizontal speed v. While bringing the ball to rest, her hanv6yjb- +areu* d moves back a distanced. Assuming constant deceleration, the horizontal force exerted on the ball by her hand is

  99.14: A construction laborer holds a 20 kilogram sheet of f9ufu odh0.+lwallboard 3 meter above the floor for 4 seconds. Durhduou90ff+l . ing these 4 secondshow much power was expended on the wallboard?

  17.11: A 5.00 kg block slides with uniform acceleragrm(7 d ,o8uhhtion on a horizontal surface for 5.00 s. The block’s kinetic energy strictly decreases from 50.0 J to 20.0 J in this tim8m(or7hgdh, u e.
What is the average speed of the block during the motion described?

  17.12: A 5.00 kg block slides with uniform acceleration on a horizontae5o 3 8kpy8. ;qxdudpql surface f8 eok; qudppqy.53 d8xor 5.00 s. The block’s kinetic energy strictly decreases from 50.0 J to 20.0 J in this time.
Which one of the following choices best represents the magnitude of the block’s acceleration during the motion described?

  16.11: A 12.0 N net force directed to the right i5p12aqi s t2rns exerted on a 3.0 kg block for 5.0 s. The block was inirn as1tip225 qtially at rest and slides on a horizontal surface.
What is the speed of the block at the end of the 5.0 interval?

  16.12: A 12.0 N net force directed hl/dvq tw19:tto the right is exerted on a 3.0 kg block for 5.0vq:w9d/1tl th s. The block was initially at rest and slides on a horizontal surface.
What is the kinetic energy associated with the block after the 5.0 interval?

  00.15: A student initially at reston a frictionless frozen pond throws a 1sllaq; l0;9x g kg hammer in one direction. After the throw, the hammer moves off in one direction while the student moves off in the other direction. Which of the following correcqlsx;a;9gl 0l tly describes the above situation?

  03.14: A fan blows the air and gives it kinetic energy. An hour after t -/nf jtor 0bya2 j:sfj-: r:hfjeo17the fan has f jt/jj12rf:n-h-o:tjsf: oye b7a 0r been turned off,
what has happened to the kinetic energy of the air?

  09.05: At an instant, a block of mass 0.50 kmn8 6n, k:mi,mqnmj3:bf .tgbg has a position of 3.0 m, a speed of 4.0 m/s, and an acceleration of m.jm nf6g,:3b,: ntnm8q kmi b$1.0\; m/s^{2}$ . What is the kinetic energy (in Joules) at this instant?

  05.05: A box of old textbooks is on the middle shelf i ;ukcw: :sw9fdn the bookroom 1.3 m from the floor. If the janitor relocates the box to the shelf that is 2.6 m from the floor, how much work does he ;dws:c :u f9kwdo on the box. The box has a mass of 10.0 kg.

  02.32: An automobile engine delivers 24,000 watts (about 32 hohs7gs41y2jy x+ no6 marsepower) of power to a car's driving wheeoyy1s2an6 sx+m7h4j gls. If the car maintains a constant speed of 30 m/s (about 65 mph), what is the magnitude of the retarding force acting on the car?

  09.13: In the figure to the right, a box moves wragfhn jk s/(b5uy8 eeaq )6+dbw+9* xith speed 5.00 m/s at the bottom of a rough, fixed inclined plane. The box slides with constant acceleration to the top of the incline as it is being pushed directly to the left with a constant force ofF = 240N. The box, of mass m= 20.0 kg, has a speed of 2.50 m/swhex9q(ykg +bus *6e wn8hjf)a+ed/abr5n it reaches the top of the incline.
What is the magnitude of the acceleration of the box as it slides up the incline?

  09.14: In the figure to the oh b*bpsh-o 4a.1y:ya right, a box moves with speed 5.00 m/s at the bottom of a rough, fixed inclined plane. The box slides with constant acceleration to the thb-.4sy ap:ha *ybo1oop of the incline as it is being pushed directly to the left with a constant force of F = 240N. The box, of mass m= 20.0 kg, has a speed of 2.50 m/swhen it reaches the top of the incline.
How much work is done by the applied force F to the box?

  11.30: Two cars travel to the right, each starting from rest,mf+tab;bi6z ae6/d7 yzbm)5z along a straight road. CarA has twice the acceleration of Car B. After traveling a distance F, Car A has speed B. When Car B has traveled the same d+ita6b)z5; 7bze/dfa6m zybm istance F, what is its speed in terms of B?

  12.07: What is the net force acting on the objectqzx6/ b c9d,nz during the time interval of the acx6,9dz qb/cznceleration?

  12.08: Through what distance does the object move during the time interval of rs *zv 94(04xteiaswj the z j(i0*atses x4r vw94acceleration

  12.19: The magnitude of the linea.t qb-6r6v 2 tyc,nyevr momentum of a 4.00 kg point mass is changed from 6.00kg.m/s to 14.0kg.m/s in a time intervat-bv6 .q6c eyytv2r n,l of 6.00 s. What is the change in the kinetic energy of the mass during this time interval?

  14.11: A crate gainsdpn9yf:73) ;wz:uq* fgux nen 36.0 J of kinetic energy while its speed is increased from 2nf*pfd :xuy73 q: g;nwe9)nzu .00m/s to 4.00m/s. Which one of the following choices best represents the mass of the crate

  94.38: A force F at an angle θ above the horizontal is used to pttusiah 22+)moc56rg8:qggnq ,, cekull a heavy suitcase of weight mga distance d along a level floor at constant velocity. The coefficient of friction between the raen qctiq6, 2ch:omg +kug25,ts g)8floor and the suitcase is μ. The work done by the frictional force is:

  14.31: A toy crane exerts an upward fx;h((wqih k,korce and delivers a useful power output of 0.10 w to raise a block vertically at a constant speed. At what constant speed will this crane raise a 0.20 kg bihh;, w(kq x(klock?

  12.18: A 1.00 kg object is released from rest near the su:mllh) lno69qb6 xq2 lrface of the Earth, the gravitational force acting on the 1.00 kg object by the Earth does 10.0 J of work on the object as it falls 1.00 mto the ground, whil29qb) :lmlo6nx lh6 qch one of the following choices best represents the amount of work done by the gravitational force acting on the Earth by the 1.00 kg object during the fall?

  96.18: A rubber ball is held motionless a height ho above a hard floor ansger a1zc d7+0d released. Assuming that the collision with the floor is elastic, which one of the following graphs best shows the relationship between the total energy E of the ball an cdgs0e+1z7rad its height h above the surface?

  07.06: A 500-kg car is moving at 28 m/s. The driver sees a barrier u6 hq)qn,wp *yahead. If the car takes 95 meters to come to rest, what is the magnitude of the minimum average net force necessary to stowuq 6y hn,)*pqp?

  00.26: A 500-gram ball moving at 15 m/s slows down uibw w h*,xagmdp* d,g6)7j5l rniformly until it stops. If the bwhgm* d ,x7)gbjr* 6dl5 wipa,all travels 15 meters, what was the average net force applied while it was coming to a stop?

  02.26: Consider two laboratory carts of different masses 5,cy)cm2ija8b 2w ;prqd qpz8but identical kinetic energies and the three following statements. Which of the above statements would be corre)b p8iz85qa q2 c pdm,crwj;y2ct?
I. The one with the greatest mass has the greatest momentum
II. The same impulse was required to accelerate each cart from rest III. Both can do the same amount of work as they come to a stop

  06.19: A 60.0-kgball of clay is toss,.quuhgf ,p;x-z k5cced vertically in the air with an initial speed of 4.60 m/s. Ignoring air ruk.up - cgz,;fc hx5q,esistance, what is the change in its potential energy when it reaches its highest point?

  06.20: A boy jumps from rest s5/ t yxc)mh5estraight upward from a flat, stationary concrete surface. The boy, of mass M, leaves the concrete surface with speed v and his center of mass rises a distance d to the highest point of the motion. How much physice/c5xm s5)yhtal work did the average normal force of contact (N) between the boy’ s feet and the concrete do on the boy?

  02.48: An object of mass M is dropped from aheightH above the ground. Theq emg,( wj0ggx4xlu-k n;0 -wv0 wnb3v object crashes into some soft earth and comes to rest by compw0mgxv(g, vwel0u0qwx n4b n 3k-;-jg ressing the earth a distance of H/2. Assuming that air resistance is negligible, what is the magnitude of the average constant force exerted by the ground on the object while coming to rest?

  12.48: An object of mass M is dropped from ahckfp( djh2* qk:z,mi 7eight H above the ground. The object bounces off of a horizontal surface idq(h7:mz*j f ,kkcip2n a collision lasting time T. The object then rises upward to a maximum height H/2. What was the magnitude of the average net force acting on the mass during the collision with the surface?

  96.38: A pendulum bob mass mon a cord length L is pulled sidek-j5tmg+a.f +jgz vsjkm 47,g je0.hqways until the cord makes an anglez5 7gkvm.0fjm+qk-t g,.sjhj4+a gje
θ with the vertical as shown in the figure to the right. The change in potential energy of the bob during the displacement is:

  03.49: A sled slides up a uniform mn71 hh 251wrbddp )k*tuc.qn incline of unknown angle. The sled, which started at the bottom of the incline moving at 10.0 m/s, rises to a height of 3.30 m above n dk5 tqmuchpd*1wh).r12n7bits starting position and momentarily comes to rest. The sled then slides back down the hill. What is the sled's speed when it returns to its original position at the bottom of the hill?

  06.09: A deliveryman moves 10 cartons from the sidewalk, along a 10-meter ramp(t0xw:vn vo -e woq42t to a loading dock, which is 1.5 meters above the sidewalk. If each carton has a mass of 25 kg, what is the total work done by the deliveryman on the cartons to move them to the loading dov 2wqn4-:x0we ttv o(ock?

  12.16: A constant force F=50N (as shown in the figure) is applied flyr9gf, / lu7yug1 k:kor the 6.0 meter motion of the box upward along the incline. The mass of the block is M=15 kg. Which one of the following choicl9:u l7ur,y /yk1gkfges best represents the work done by the force F onthe box for the motion?

  04.48: Two identical bowling ballkc ttn* 1anr62s A and B are each dropped from rest from the top of a tall tower. Ball A is dropped one second before ak tn2c6n*t1rball B. After ball B is dropped but before ball A strikes the ground, how are the mechanical energies of the two balls changing?

  11.28: A person throws an objgculqr7; lv2 s2z7o.q -y .gbk y1lpv)ect of mass M straight upward with an initial non-zero speed v. The object rises to a l2gyopq;glcq27 v.sv7 zy)1 lb.-rukmaximum height H above the launch point. The person now throws an object of mass 0.5M straight upward with initial speed 2v. In terms of H, to what maximum height does the object of mass 0.5M rise above the launch point? Ignore air resistance.

  96.20: A force of 10 N stretches a spring that has a spring cok nzn* 6kbw2k n5;lc0wnstant of 20 N/m. The potential energy stored in the sprin;kwk 56 b0 cnknzwl*n2g is:

  97.10: A compressed spring has 16 J of potential energy. What is the maxim+e+hn r-2*vnjo t1mttum speed it can impart too1mrhtn*- +et2 vtj +n a 2.0-kg object ?

  

  10.31: An object of mass M starts from rest at the bottom of a fixed incline p znb2(ri7nv8x h4 xp2c7nvp1of height H. A person decides to push the object up the incline in one of two ways with an applied force shown in the diagram. In each of the trials, the object reac1b r7n28pv i 4xcn2xnp z(v7phhes the top of the incline with speed V. How would the work done by the person on the block compare for the two trials? Assume the same constant non- zero coefficient of kinetic friction between the incline and the object for both trials.