the sound coming from one tuning fork can force another to vibrate. what is the analogous effect for light?

How would doubling the made of an object change the objects potential energy

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?

Marvin records scientific data about lake superior. for which property has marvin forgotten to use an si unit of measurement? shore length high temperature low temperature annual precipitation