To calculate the potential energy of an object at a certain height, you can use the formula:
Potential energy = mass × gravitational acceleration × height
Given: Mass (m) = 20 g = 20/1000 kg = 0.02 kg (converted to kilograms) Height (h) = 40 m Gravitational acceleration (g) = 9.8 m/s² (approximate value on Earth)
Potential energy = 0.02 kg × 9.8 m/s² × 40 m
Calculating the potential energy:
Potential energy = 0.02 kg × 9.8 m/s² × 40 m = 7.84 J (joules)
Therefore, the potential energy of the ball when it reaches the maximum height is 7.84 joules.