GED Science TestPhysical ScienceMedium
A student is investigating the relationship between the mass of an object and its gravitational potential energy. They lift a 2 kg mass to a height of 3 meters. If the acceleration due to gravity is approximately 9.8 m/s², what is the gravitational potential energy of the mass at that height?
- A6 J
- B19.6 J
- C60 J
- D58.8 J
Show answer & explanationAnswer & explanation
Correct answer: D. 58.8 J
Gravitational potential energy (PE) is calculated using the formula PE = mgh, where m is mass, g is acceleration due to gravity, and h is height. Plugging in the values: PE = 2 kg * 9.8 m/s² * 3 m = 58.8 Joules.
Why the other options are wrong
- A. This would be the result if gravity was approximated as 1 m/s² (2*1*3=6), which is incorrect.
- B. This would be the result if the mass was 1 kg and g was 9.8 m/s² and height was 2m (1*9.8*2=19.6), or some other incorrect combination.
- C. This would be the result if gravity was approximated as 10 m/s² (2*10*3=60), which is a common approximation but not the value given.
Gravitational Potential Energy
The energy an object possesses due to its position in a gravitational field, typically its height above a reference point.
- PE = mgh (mass * gravity * height)
- Measured in Joules (J)
- Increases with mass and height
Memory trick: Mass, Gravity, Height make 'Mighty' Potential Energy.