Belly-flop Bernie dives from atop a tall flagpole into a swimming pool below. His potential energy at the top is 7000 J (relative to the surface of the pool). What is his kinetic energy when his potential energy reduces to 1000 J?

KE₂ = 6000 J

Explanation:

Given that

Potential energy at top U₁ = 7000 J

Potential energy at bottom U₂ = 1000 J

The kinetic energy at top, KE₁ = 0 J

Lets take kinetic energy at bottom level = KE₂

Now from energy conservation

U₁ + KE₁ = U₂ + KE₂

Now by putting the values

U₁ + KE₁ = U₂ + KE₂

7000 + 0 = 1000 + KE₂

KE₂ = 7000 - 1000 J

KE₂ = 6000 J

Therefore the kinetic energy at bottom is 6000 J.