Physics Question. Please look at attached.

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?

The particles that are found in the nucleus of an atom are

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in