Convert 64,000 cm to m

Can anybody me with this? ? (picture included.)

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?

Sound is a disturbance that travels through a medium as a