To calculate the gravitational potential energy (PE) of the apple, you can use the formula:
\[ PE = mgh \]
where:
- \(m\) is the mass of the object (in kilograms),
- \(g\) is the acceleration due to gravity (approximately \(9.81 , \text{m/s}^2\) on the surface of the Earth),
- \(h\) is the height above the ground (in meters).
For your apple:
- \(m = 4 , \text{kg}\)
- \(g = 9.81 , \text{m/s}^2\)
- \(h = 2 , \text{m}\)
Now plug in the values:
\[ PE = 4 , \text{kg} \times 9.81 , \text{m/s}^2 \times 2 , \text{m} \]
\[ PE = 4 \times 9.81 \times 2 \]
\[ PE = 78.48 , \text{J} \]
So, the gravitational potential energy of the apple is approximately 78.48 joules.