Exam 2 Key: Exam 2A Exam 2B 1 B B 2 A B 3 A B 4 B B 5 B A 6 B A 7 A B 8 A A 9 B A 10 B B Same from here down. A A C B E B D B B C D B A E B
True/False Section: each question worth 3 points.1.An elevator car starts from rest on the ground floor, then accelerates upward and stops on the 10thfloor above. The net work done on the elevator car is positive. 2.A block is at rest on a horizontal table. A (nonzero) horizontal force pushes on the block but the block does not move due to static friction with the table. The magnitude of the friction force must be equal to the coefficient of static friction multiplied by the weight of the block(࠵?!=࠵?!࠵?࠵?). 3.Two springs of equal length have two different spring constants, ࠵?!>࠵?!. Both springs are compressed by the same amount, ࠵?࠵?. Both springs have the same potential energy.4.A massive rocket and a light bullet are accelerated from rest to different final speeds. The net work done on both objects cannot be the same.a.True b.False 5.An empty bottle sits on a horizontal table. Nothing contacts the bottle except the table. The table accelerates to the right and the bottle starts to slide. The force of kinetic friction from the table on the bottle acts to the right.6.Two blocks of equal mass slide down two different frictionless ramps from the same height. One ramp is steeper than the other. The two blocks have the same speed at the bottom of each ramp.7.A spring is compressed a distance ࠵?࠵?from its equilibrium length. If the spring is then compressed by 2࠵?࠵?from equilibrium, its potential energy increases by a factor of 2.