An electrician must decide between 3 heaters. the wire that she is using is rated 15a maximum, anything beyond that is a fire hazard. two of the heaters operate off a standard 120v circuit. one is rated 900w and the other 1800w. the third operates off a 240v circuit and can deliver 3000w of power. calculate the amount of current for each.

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?