Question:
A block of mass $5.0 \mathrm{~kg}$ slides down an incline of inclination $30^{\circ}$ and length $10 \mathrm{~m}$. Find the work done by the force of gravity.
Solution:
Work done,
$\mathrm{W}=\mathrm{mgh}$
$=5 \times 9.8 \times\left(\sin 30^{\circ} \times 10\right)$
$W=245 \mathrm{~J}$