Question

9. If the amount delta X by which a spring is compressed is doubled, the potential energy stored in the spring ______

stays the same

quadruples

halves

doubles

11. A mass M is hanging at the bottom of a vertical spring. After being pulled down and released, the mass oscillates down-up-down with a period T. If the mass is quadrupled, the period T of oscillation _____

halves

stays the same

doubles

quadruples

12. A car having mass M₁= 2000 Kg moving with an unknown initial velocity V_1icolides with a car having mass M₂= 3000 Kg that was initially at rest (V_2i=0). After making inelastic collision, the cars stick together and move through a distance d= 128 m (length of skid mark ) until they stop. The net frictional force exerted on the coupled cars was NEGATIVE 20, 000 N. The initial velocity of the 2000 Kg car before the collision is  V_1i  =_______ m/s

12.8

80

128

32

Answer 1