$A$ person is climbing a palm tree:
$(i)$ What is the work done against the force of gravity?
$(ii)$ What is the work done by the force applied by the person if the person climbs $10 \, m$ and the mass of the person is $45 \, kg$?

(D) $(i)$ The work done against the force of gravity is equal to the change in gravitational potential energy,which is given by the formula $W = mgh$,where $m$ is the mass,$g$ is the acceleration due to gravity,and $h$ is the height.
$(ii)$ Given: mass $(m) = 45 \, kg$,height $(h) = 10 \, m$,and acceleration due to gravity $(g) \approx 10 \, m/s^2$.
Work done $(W) = m \times g \times h$
$W = 45 \, kg \times 10 \, m/s^2 \times 10 \, m$
$W = 4500 \, J$.