Suppose an acorn with a mass of 3.17 g falls off a tree. At a particular moment during the fall, the acorn has a kinetic energy of 0.259 J and a potential energy of 0.207 J with respect to the ground. How does the acorn's potential and kinetic energy change as it falls

potential energy decrease and kinetic energy increases.

Explanation:

the law of conservation of energy says that the total energy of a system is conserved, then:

where is the initial kinetic energy, is the initial potential energy, is the final kinetic energy and is the final potential energy.

so, when the acorn fall the final potential energy is going to decrease because the potential energy is equal to:

Where m is the mass, g the gravity and h the height.

Therefore, in order to fullfil with the law of conservation of energy is necesary that the final kinetic energy increase.

Now, we know that the kinetic energy is equal to:

where v is the velocity, so, it means that the velocity of the acorn is going to increase.      

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.