What are the top three materials by weight in a computer

What is the power rating of the lightbulb if 3.0 a flow through it when connected to a 15 v battery

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 kind of simple machine is a catapult?