Question

In which case is potential energy increasing?

A.
a 20 kilogram boulder rolls down a hill that is 430 meters high
B.
a weightlifter lifts a 20 kilogram barbell above his head
C.
a skydiver jumps from an airplane that is 4 kilometers above the Earth
D.
a spring of a dart gun launches a dart in a straight line from rest position

Answer 1

I think it's B " Weightlifter lifts a 20 Kg barbell above his head"

Answer 2

a weightlifter lifts a 20 kilogram barbell above his head