Question:
Figure shows a man of mass $60 \mathrm{~kg}$ standing on a light weighing machine kept in a box of mass $30 \mathrm{~kg}$. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight shown by the machine? What force should he exert on the rope to get his correct weight on the machine?
Solution:
(A)
(B)
$a=3 g$
$\mathrm{T} 1=60 \mathrm{a}=60 \times 3 \mathrm{~g}=1800 \mathrm{~N}$