A force of 315N is applied horizontally to a wooden crate in order to displace it 35m across a level floor at a constant velocity.

A force of 315N is applied horizontally to a wooden crate in order to displace it 35m across a level floor at a constant velocity. As a result of this work the crate’s internal energy is increased by an amount of 14% of the crate’s initial internal energy. Calculate the initial internal energy of the crate.