If two uncharged objects are rubbed together and one of them acquires a negative charge, then the other one
a. remains uncharged
b. acquires a positive charge equal to twice the negative charge
c. also acquires a negative charge
d. acquires a positive charge acquires a positive charge equal to half the negative charge

The two required components for a generator are

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?