The blanks are filled using the fundamental definitions of work, energy, and power. Work done is defined as the product of force and displacement in the direction of the force. One joule of work is done when a force of 1 newton displaces an object by 1 metre. The kinetic energy of a body is expressed as half the product of its mass and the square of its velocity (1/2 mv²). The potential energy of an object at a small height h from the Earth's surface is given by mgh. Power is defined as the rate at which work is done.