Question

A body of mass 2 kg is raised to a height of 5 m. What is the potential energy gained? (Take $ g = 10 \, \text{m/s}^2 $)

• A. 10 J
• B. 50 J
• C. 100 J
• D. 150 J

Hint:

Gravitational potential energy is given by \( PE = mgh \). Always use consistent units: mass in kg, height in meters, and \( g = 9.8 \) or 10 \( \text{m/s}^2 \) as approximated. This formula tells you how much energy is stored due to elevation.

Answer 1

The Correct Option is C

The potential energy gained by a body raised to a certain height is given by the formula:
\[ PE = mgh \] Where:
\( m \) = mass of the body = 2 kg
\( g \) = acceleration due to gravity = 10 \( \text{m/s}^2 \)
\( h \) = height = 5 m
Step 1: Substitute the values into the formula
\[ PE = 2 \times 10 \times 5 = 100 \, \text{J} \] Step 2: Interpretation
The body has gained 100 joules of gravitational potential energy as a result of being raised. This energy is stored due to its position above the ground and can be converted into kinetic energy if it falls.
Why not the other options?
- 10 J and 50 J are too low, based on the formula.
- 150 J would require a greater height or mass.