Kinetic energy is a form of energy that an entity or particle possesses due to its motion.

The relation between the object's mass and its speed.

KE = \frac{1}{2} mv^2

The energy contained in an object due to its location is known as potential energy.

PE = mgh , where, m - mass,  g - acceleration due to gravity and h - height.

Law on energy conservation:

Energy can neither be created nor destroyed, but it can be converted from one form to another.

When the object is dropped we initially have only potential energy, which is later transformed to kinetic energy. So according to the law of conversion kinetic energy is equal to potential energy.


Step 1: Determine the kinetic energy of the object

Given that

Rock mass m = 0.2 kg

Height of the helicopter h = 12 m

Acceleration due to gravity g = 9.8 m/s

According to the law of conversion, kinetic energy is equal to the potential energy  


KE = mgh

KE = (0.2kg)(9.8 m/s^2)(12 m)

KE = 23.52 kg m^2/s^2    

Hence, kinetic energy of the rock   KE = 23.52 joules.