A block of mass 6 kg is suspended by a rope of mass $2 \mathrm{~kg} . \mathrm{T}_{\mathrm{A}}$ is te

Question

A block of mass 6 kg is suspended by a rope of mass $2 \mathrm{~kg} . \mathrm{T}_{\mathrm{A}}$ is tension in the rope at the point $A$ and $T_B$ at $B$. Then $T_A-T_B$ is

Professor PC Thomas Classes · Answer

Let $A$ be the top of the rope, $B$ be the bottom. $T_A = (m_{block} + m_{rope})g = 8g$. $T_B = m_{block}g = 6g$. $T_A - T_B = 2g = 20 \mathrm{N}$. (Or taking ratio, $2g=19.6 \approx 20\mathrm{N}$ if $g=9.8$, but exact is weight of rope = $2\mathrm{kg} 	imes g$).