an object of mass m is at rest at the top of a smooth slope of height h and length l. the coefficient of kinetic friction between the object and the surface, ? k, is small enough that the object will slide down the slope if given a very small push to get it started.
1. find an expression for the object's speed at the bottom of the slope.
2. sam, whose mass is 70kg , stands at the top of a 10-m-high, 80-m-long snow-covered slope. his skis have a coefficient of kinetic friction on snow of 0.07. if he uses his poles to get started, then glides down, what is his speed at the bottom?

Aquantity of gas has a volume of 1.5 m3 and an absolute pressure of 95 kpa. when the gas is compressed to a volume of 0.5 m3, what is the new absolute pressure of the gas? (assume that there’s no change in temperature.)

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.