A mass of 1 kg is suspended by means of a thread. The system is (i) lifted up with an acceleration of 4.9 m s- 2 (ii) lowered with an acceleration of 4.9 m s- 2 . What is the ratio of tension in the first and second case?

Question

A mass of 1 kg is suspended by means of a thread. The system is (i) lifted up with an acceleration of 4.9 m s- 2 (ii) lowered with an acceleration of 4.9 m s- 2 . What is the ratio of tension in the first and second case? (A) 3:1 (B) 1:2 (C) 1:3 (D) 2:1

Tardigrade Admin · Accepted Answer

Case-I:

Using newton’s second law of motion, T1- mg=ma T1=m (g + a) Case – II: Solution

Using newton’s second law of motion mg-T2=ma T2=m (g - a) From equation (i) and (ii) (T1/T2)=(g + a/g - a)=(9.8 + 4.9/9.8 - 4.9)=(3/1)

Q. A mass of $1 k g$ is suspended by means of a thread. The system is (i) lifted up with an acceleration of $4.9 m s^{- 2}$ (ii) lowered with an acceleration of $4.9 m s^{- 2}$ . What is the ratio of tension in the first and second case?

$3 : 1$

$1 : 2$

$1 : 3$

$2 : 1$

Case-I:

Using newton’s second law of motion,
$T_{1} - m g = ma$
$T_{1} = m (g + a)$
Case – II:

Using newton’s second law of motion
$m g - T_{2} = ma$
$T_{2} = m (g - a)$
From equation (i) and (ii)
$\frac{T _{1}}{T _{2}} = \frac{g + a}{g - a} = \frac{9.8 + 4.9}{9.8 - 4.9} = \frac{3}{1}$

Q. A mass of 1kg is suspended by means of a thread. The system is (i) lifted up with an acceleration of 4.9ms−2 (ii) lowered with an acceleration of 4.9ms−2 . What is the ratio of tension in the first and second case?

3:1

1:2

1:3

2:1