Is it skier going down a hill balanced or unbalanced force?

Explanation:

The skier's speed increases going down the hill because forces F3 and F4 are unbalanced, with F3 acting in the same direction as the velocity, causing the skier to speed up

a) electrical > light, sound, and thermal< < < <

) the mechanical energy of the firefighter moving.< < < < a) electrical > light, sound, and thermal< < < <

c) both a and b.