Q. A mass $1\ kg$ is suspended by a thread. It is (i) lifted up with an acceleration $4.9\ m/s^{2}$ (ii) lowered with an acceleration $4.9\ m/s^{2}$ The ratio of the tension is
A) $3:1$
B) $1:3$
C) $1:2$
D) $2:1$
Explanation
(a) $T_{1} = m(g + a) = 1 \times \left( g + \frac{g}{2} \right) = \frac{3g}{2}$
$T_{2} = m(g - a) = 1 \times \left( g - \frac{g}{2} \right) = \frac{g}{2}\ \therefore\frac{T_{1}}{T_{2}} = \frac{3}{1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.