As the swing moves from point b to point a, which form of energy is increasing, kinetic or potential?

The kinetic energy

Explanation:

The potential energy (P) is the energy that the swing has due to its position, and it can be calculated with the expression

P = m . g . h

where,

m: mass

g: gravity

h: height

The higher is the swing, the more potential energy it has.

On the other hand, the kinetic energy (K) is the energy which a body possesses by virtue of being in motion, and it can be calculated using the expression

K = 1/2 . m . v²

where

v: speed

In B, the swing is virtually still (v = 0), while in A, v is maximum and so is its kinetic energy.

Then, as the swing moves from point B to point A, the kinetic energy increases and the potential energy decreases.