A slingshot obeys Hooke's law and is used to launch pebbles vertically into the air. You observe that if you pull a pebble back 20 cm against the elastic band, the pebble goes 6 m high. Assuming that air drag is negligible, if you pull a pebble that is twice as heavy back 20 cm, how high will it go?
4 m
5 m
3 m
6 m

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.

What are the north and south poles of a solenoid change with?

A1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. what is the magnitude of the friction force required to keep the car from sliding?