Description
In a given system, there is positive work done and the potential energy is found to have increased. Can you tell if the amount of kinetic energy has increased, decreased, or stayed the same? Explain
Explanation & Answer
Yes, you can. The total energy of a system *must* remain constant. So E = kinetic energy + Potential energy.
If Potential Energy changes, E has to remain the system. So:
E = K + P
E = K + Increase in P
E must stay the same, so there must be a decrease in kinetic energy
TO put it another way, in simpler terms:
If E = 10, K = 5 and P = 5, then:
10 = K + P
10 = 5 + 5
Potential energy increases by 1
10 = 5 + 6, but that isn't right, so kinetic energy must have changed:
10 = 4 + 6