Question

Calculate the kinetic energy of a rock that has a mass of 55 kg rolling down a hill with a velocity of 8 m/s.

Answer 1

Answer:

The answer is 1760 J

Explanation:

Given:

m = 55 kg

v = 8 m/s

Unknown:

KE or kinetic energy of the rock

Formula and solution:

KE = 1/2 mv²

KE = 1/2 (55kg) (8 m/s)²

1/2 of 55kg = 55 ÷ 2 = 27.5kg

8² or 8×8 = 64 m²/s²

KE = (27.5kg) (64 m²/s²)

Final Answer:

KE = 1 760kg.m²/s² or simplify as 1760 J