Power

The power delivered to a body is the rate at which work is done, and it can be expressed as: Where:
is the power,
is the force,
is the velocity.
For a body undergoing motion with constant acceleration, the velocity at any time is given by: Where is the constant acceleration. The force acting on the body is given by Newton's second law: Where is the mass of the body and is the acceleration. Substituting the expressions for and into the equation for power: Since the body starts from rest and has constant acceleration, the power delivered to the body is proportional to .
Thus, the power delivered to the body at time is proportional to .

The correct answer is (B) : t.