P211 MT2 Fall 2004 Form A35/41.A student wants to determine the coefficients of static friction and kinetic friction between a box and a plank.She places the box on the plank and gradually raises one end of the plank. When the angle of inclination withthe horizontal reaches 27.5°, the box starts to slip and slides down the plank in 4.1 s. The coefficient of staticfriction is:A.0.425B.0.462C.0.479D.0.521E.0.88735/62.A trunk with a weight of 250 N rests on the floor. The coefficient of static friction between the trunk and thefloor is 0.42, while the coefficient of kinetic friction is 0.20. If the trunk is pushed with the minimum forcerequired to start the trunk moving and continues to be pushed with this force, how far will the trunk havemoved after 5 s?A.25.7 mB.2.5 mC.24.5 mD.2.75 mE.27 m37/173.A small block of mass M is released at rest from the inner edge of a frictionless, stationary, semicircular bowland slides down. What can you say about the normal force |N1| on the block just after it is released and thenormal force |N2| on the block when it is at its lowest point?N1N2A.|N1| < Mg and |N2| = MgB.|N1| = Mg and |N2| > MgC.|N1| < Mg and |N2| < MgD.|N1| < Mg and |N2| > MgE.|N1| > Mg and |N2| = MgPage 1P211 MT2 Fall 2004 Form A43/44.ˆˆAt time 0 a 2 kg particle has a velocity of (4 m/s) i - (3 m/s) j. At 3s its velocitytt==ˆˆis (2 / ) (3 / ) . During this time the total work done on it was:msi m s j+A.-40 JB.-12 JC.-4 JD.4 JE.ˆˆ(4J) i + (36 J) j40/125.A woman lifts a barbell 2.0 m in 5.0 s. If she lifts it the same distance in 10 s, the work done by her is:A.one-fourth as greatB.one-half as greatC.the sameD.two times as greatE.four times as great40/106.A 100 kg hockey player skates at 2.5 m/s toward a railing at the edge of the ice and then stops himself bygrasping the railing with his outstretched arms. During the stopping process his center of mass moves 40 cmtoward the railing. What average force must he exert on the railing?A.7.8 NB.15.6 NC.781 ND.1562 NE.3125 N47/87.A Physics 211 student watches a maple leaf gently fall from a tree on a calm autumn day. The leaf is falling atconstant speed, and she draws the following conclusions. Which, if any, are TRUE?i) The net force on the leaf is zero.ii) The work done by air resistance has the same magnitude as the work done by gravity.iii) The mechanical energy K+U is a constant during the fall of the leaf.iv) The work done by air resistance on the leaf is negative.A.iii) and iv) onlyB.i) and ii) onlyC.i), ii), and iv) onlyD.i), ii) and iii) onlyE.all four statements are truePage 2P211 MT2 Fall 2004 Form A48/48.A large block of cheese, attached securely to a bungee cord, is released from rest from a stationary helicopter.The helicopter is 50 meters above the ground. The bungee cord has an unstretched length of 20 meters and aspring constant of 50 Newtons per meter. The mass of the cheese is 100 kg. Unfortunately the helicopter istoo low and the cheese hits the ground. With approximately what velocity does it hit the ground?A.0 m/sB.16 m/sC.24 m/sD.32 m/sE.50 m/s48/169.An object of mass m slides without rolling down the frictionless fun-slide depicted in the figure. If the objectbegins sliding from rest at the top of slide, what is the ratio of the speed of the object at B to the speed of theobject at A?A.2 to 1B.2 to 1C.3 to 2D.3 to 2E.3 to 448/1910.A 1 kg ball is loaded into a spring gun with a spring constant of 105 kg/s2. If the spring is compressed by 10cm and the ball is shot up vertically, how high does it rise into the air?A.12.7 cmB.1.3 mC.12.7 mD.102.0 mE.51.0 mPage 3P211 MT2 Fall 2004 Form A49/311.The first graph below shows the potential energy, U (x) for a particle moving along the x axis. Which of thefollowing five graphs correctly gives the force F(x) exerted on the particle?A.IB.IIC.IIID.IVE.V51/212.A 25 kg bear slides, from rest, 8m down a lodgepole pine tree, moving with a speed of 5.7 m/s just beforehitting the ground. What is the average frictional force that acts on the bear?A.0 NB.195 NC.780 ND.1550 NE.2450 N61/1213.Superman (mass = 78.0 kg) stops a train (mass = 18619 kg) headed for a broken bridge. The train wasinitially traveling at 60.0 km/h. During the constant deceleration, the passengers experience an averagehorizontal force of 0.410 their own weight. How long does it take for the train to come to a stop?A.14.93 sB.6.12 sC.1.70 sD.57.55 sE.4.15 sPage 4P211 MT2 Fall 2004 Form A61/514.A 2 kg particle traveling with a speed of 2.5 m/s as shown is acted on by a force that changes its velocity. Thefinal velocity is 1 m/s in the opposite direction. If +v is to the right, what is the impulse given to the block ( inkg m/s)?2.5 m/s(before) (after)1 m/sA.5.0B.7.0C.3.0D.-7E.057/1115.Daniella and ChiChi stand on a frictionless cart on one side of the room while Austin stands on a secondfrictionless cart on the opposite side of the room. Both carts are initially at rest, and a long rope is strewnbetween them. The girls pull as hard as they can on the rope, while Austin merely holds on to his end. A shortwhile later the carts collide. Which of the following must be true?A.Austin's cart would have moved a greater distance if he'd been the one pulling on the rope.B.Daniella & ChiChi's cart would have moved a greater distance if Austin had been the one pulling onthe rope.C.The point of collision will be halfway between the initial separation.D.The point of collision depends upon who pulls the rope.E.The point of collision will be the location of center of mass of the system.63/616.A tomato and a tennis ball of the same diameter are dropped on the floor from a height h. The tennis ballbounces higher because:A.Momentum is not conserved when the tomato hits the floor.B.Energy is lost to distortion of the tomato on impact.C.Momentum is not conserved when the tennis ball hits the floor.D.There is much more air resistance against the tomato while it is falling.E.There is a higher coefficient of friction between the tomato and the floor.63/817.A hawk and a quail (mhawk > mquail) are moving directly toward each other. The birds collide and sticktogether (via the hawk's talons). Which of the following is true concerning this collision?A.The