In a bungee jump where the total energy at the top is 60,000 J and air resistance is ignored, which energy store of the person decreases as they fall?

What the question is asking

You are identifying which energy store gets smaller while the jumper moves downward, assuming no energy is lost to air resistance.

Linking energy stores to what changes during a fall

• The jumper’s height above the ground decreases.
• Gravitational potential energy depends on height: $$E_p = mgh$$ So when $h$ goes down, $E_p$ goes down.

Where that energy goes (since air resistance is ignored)

Because mechanical energy is conserved here, the decrease in gravitational potential energy is transferred into other stores:

• mainly the kinetic energy store of the person: $$E_k = \tfrac{1}{2}mv^2$$
• and, once the cord begins to stretch, the elastic potential energy store of the bungee cord.

Quick check

At the very start of the fall the jumper speeds up, which is exactly what you expect when gravitational potential energy is decreasing and becoming kinetic energy.