Which one is it plzz help

Stayed the same

Explanation:

Potential energy is a function of mass, gravity and height relative to a reference level. If we take as the reference level the soil, this is the level where the potential energy is zero. Since in problem it is mentioned that the track is flat, this means that there are no height changes with respect to the reference level, therefore we can say that the potential energy remains unchanged.

Ep = m*g*h

where:

m = mass [kg]

g = gravity [m/s^2]

h = elevation [m]

photocells convert light energy to electricity

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.