How much potential energy has a boy whose mass is 45 kg and who is standing on top of a 6meter high wall?
Answers
Answer:
When it’s still at the height of 10m, the object has potential energy. The formula for this is Mass x Gravitational Acceleration x Height. (m*g*h)
Mass = 20 kg
Gravitational Acceleration = 9.81 meters/(second^2)
Height = 10m
Multiplying, we get: 20 x 9.81 x 10 x (kg*meters/(second^2)) * meters
Simplifying: Potential energy = 1,962 Newton * meters = 1,962 Joules
If the object falls 10m to the ground, then right before it hits, all of its potential energy will have been converted into kinetic energy (plus a tiny bit of air friction energy lost in heat). So the kinetic energy will be 1,962 Joules *minus* some tiny amount (whatever amount of energy was lost heating up the air on the way down).
Once it actually hits the ground, its potential energy and kinetic energy will both be zero (after things have settled down). All of the kinetic energy that it had just before impact will have been converted into heat energy (heating up the object, ground, and nearby air at the point of impact). It will also make a loud “thump” sound, so a very tiny fraction of this energy will also be in the form of acoustic wave energy, most of which eventually turns into heat.
Explanation: