Question

What is the kinetic energy of the skier at a height of 60 meters above ground? (3 points)

a.20,000 units, because total energy remains unchanged

b. 80,000 units, because total energy remains unchanged

c. 20,000 units, because total energy of the skier decreases

d. 80,000 units, because total energy of the skier decreases

Answer 1

30,000 units is the right answer

Answer 2

30,000 units, because total energy remains unchanged.

Explanation:

The law of conservation of energy states that energy cannot be destroyed, it remains conserved but transforms from one form to the other form.

Hence, we can say that

Total energy = kinetic energy (KE) + potential energy (PE).

At 100 meters above

Total energy = 0 + 50000 = 50000 units.

Hence, 60 meters, total energy would be

20,000 + x = 50000 units

Finally,

x = 50,000 - 20,000

= 30,000

The energy will only transform from one form to the other but will not change.