Question

A mass 1 Kg is suspended by a thread it is
(a) lifted with an acceleration $4.9$ $m/s^2$
(b) lowered with an acceleration $4.9$ $m/s^2$
The ratio of tension is

• A. $3:1$
• B. $2:1$
• C. $1:1$
• D. $1:3$

Answer 1

The correct option is A $3:1$

Lifts up

$\therefore F_{net}=ma$

$\therefore T_1-mg=1\times 4.9$

$\therefore T_1=mg+4.9$

$\therefore T_1=1\times 9.8+4.9$

$\therefore T_1=14.7$

Lowers

$\therefore F_{net}=ma$

$\therefore mg-T_2=1\times 4.9$

$\therefore T_2=mg-4.9$

$\therefore T_2=1\times 9.8-4.9$

$\therefore T_2=4.9$.

$\therefore \frac{T_1}{T_2}=\frac{14.7}{4.9}=\frac{3}{1}=3:1$.