b) A body of mass 0.2 kg falls from a height of 10 m to a height of 6 m above the ground. Find the loss in potential energy taking place in the body. [tex]g = 10 \, \text{m/s}^2[/tex]



Answer :

To determine the loss in potential energy of a body falling from a height of 10 meters to a height of 6 meters, we can follow these steps:

1. Calculate the initial potential energy (PE_initial) when the body is at the initial height of 10 meters.
2. Calculate the final potential energy (PE_final) when the body is at the final height of 6 meters.
3. Determine the loss in potential energy by finding the difference between the initial and final potential energies.

Given:
- Mass of the body, [tex]\( m = 0.2 \)[/tex] kg
- Acceleration due to gravity, [tex]\( g = 10 \, \text{m/s}^2 \)[/tex]
- Initial height, [tex]\( h_{\text{initial}} = 10 \)[/tex] meters
- Final height, [tex]\( h_{\text{final}} = 6 \)[/tex] meters

### Step-by-Step Solution:

1. Calculate the initial potential energy (PE_initial):

Potential energy is given by the formula:
[tex]\[ PE = m \cdot g \cdot h \][/tex]

For the initial height:
[tex]\[ PE_{\text{initial}} = m \cdot g \cdot h_{\text{initial}} \][/tex]

Substituting the given values:
[tex]\[ PE_{\text{initial}} = 0.2 \, \text{kg} \cdot 10 \, \text{m/s}^2 \cdot 10 \, \text{m} = 20.0 \, \text{J} \][/tex]

2. Calculate the final potential energy (PE_final):

For the final height:
[tex]\[ PE_{\text{final}} = m \cdot g \cdot h_{\text{final}} \][/tex]

Substituting the given values:
[tex]\[ PE_{\text{final}} = 0.2 \, \text{kg} \cdot 10 \, \text{m/s}^2 \cdot 6 \, \text{m} = 12.0 \, \text{J} \][/tex]

3. Determine the loss in potential energy (loss_PE):

The loss in potential energy is the difference between the initial and final potential energies:
[tex]\[ \text{loss\_PE} = PE_{\text{initial}} - PE_{\text{final}} \][/tex]

Substituting the calculated values:
[tex]\[ \text{loss\_PE} = 20.0 \, \text{J} - 12.0 \, \text{J} = 8.0 \, \text{J} \][/tex]

Therefore, the loss in potential energy taking place in the body as it falls from a height of 10 meters to a height of 6 meters is [tex]\( 8.0 \, \text{J} \)[/tex].