Question

A car travelled 50 m in the 30s along a horizontal road. It reached the destination with a velocity 4 times of its initial velocity. During the process, what happens to the potential energy of the car?
1. Became 2 times of initial potential energy
2. Became 4 times of initial PE
3. Became 8 times of initial PE
4. Did not change

Answer 1

Correct Answer - Option 4 : Did not change

CONCEPT:​

• Potential energy: It is the energy that is conserved or stored in an object due to its arrangement, position, or state of the object or substance.

Gravitational potential energy is given by: 

​PE = m g h

where m is the mass of the body, g is the gravitational acceleration, and h is the height from the reference point.

EXPLANATION:​

Gravitational potential energy PE = m g h

Change in potential energy

ΔPE = mgΔh

• In the given question, Since the car is moving on a horizontal road, the height of the car will not change. i.e. Δh = 0

ΔPE = m g Δh = 0

• So the potential energy of the car does not change.
• Hence the correct answer is option 4.