Answer:
98.1 joule
Step-by-step explanation:
The work done in lifting a brick of mass (\(m\)) through a height (\(h\)) can be calculated using the formula for gravitational potential energy:
\[ \text{Work} = \text{Change in Potential Energy} \]
The change in potential energy is equal to the work done against gravity to lift the object to a certain height. The formula for gravitational potential energy is:
\[ \text{Potential Energy} = m \cdot g \cdot h \]
Where:
- \( m \) is the mass of the object (2 kg).
- \( g \) is the acceleration due to gravity (approximately \(9.81 \, \text{m/s}^2\) on Earth).
- \( h \) is the height (5 m).
Now, calculate the potential energy at the initial position (ground level) and at the final position (5 m above the ground):
At the initial position (ground level):
\[ PE_{\text{initial}} = m \cdot g \cdot 0 = 2 \, \text{kg} \cdot 9.81 \, \text{m/s}^2 \cdot 0 = 0 \, \text{Joules} \]
At the final position (5 m above the ground):
\[ PE_{\text{final}} = m \cdot g \cdot h = 2 \, \text{kg} \cdot 9.81 \, \text{m/s}^2 \cdot 5 \, \text{m} = 98.1 \, \text{Joules} \]
Now, calculate the work done:
\[ \text{Work} = PE_{\text{final}} - PE_{\text{initial}} = 98.1 \, \text{Joules} - 0 \, \text{Joules} = 98.1 \, \text{Joules} \]
So, the work done in lifting the brick through a height of 5 m above the ground is 98.1 Joules.