Which of the following is correct

Question

From work kinetic energy theorem ∑ W= ∧K and conservation of mechanical energy ∧U+∧K=0

Which of the following is correct?

A) ∧U= K

B) ∧U=W

C) ∧U= -K

D) ∧U= -W

(∧-DELTA)

Answer 1

∑A) ΔU = K

False.

Change in potential energy is only related to a change in kinetic energy,

not the actual amount of kinetic energy.

B) ΔU = W

False.

Positive work of a force field decreases potential energy, not increases it.

C. ΔU = -K

False.

Change in potential energy is only related to a change in kinetic energy,

not the actual amount of kinetic energy.

D) ΔU = -W

True.

Positive work of a force field decreases potential energy.

This identity follows by adding up the two given identities.

∑W = ΔK

ΔU + ΔK = 0