Question

A mass of 1 kg is suspended by a thread. It is
(i) lifted with an acceleration 4.9 m/s2
(ii) Lowered with an acceleration 4.9 m/s2. The ratio of the tension is
(a) 3:1
(c) 1:2
(b)1:3​

Answer 1

Answer:

Explanation:

Here, it is given that,

Acceleration = a = 4.9 m/s²

mass, m = 1 kg

The acceleration of gravity , g = 9.8 m/s²

The ratio of the tension = ?

Here, the magnitude of tension = T.

=> Case 1 : A mass is lifted with an acceleration 4.9 m/s².

Thus, Tension developed in the string,

T1 = mg + ma ------(1)

=> Case 2 : A mass is lowered with an acceleration 4.9 m/s2.

Tension developed in the string,

T2 = mg - ma ------(2)

=> Dividing the eq (1) by (2), we get the ratio of the tensions:

∴  T1/T2 = (g+a)/(g-a)

= 9.8 + 4.9 / 9.8 - 4.9

= 14.7 / 4.9

= 3 / 1 = 3 : 1

Thus, the ratio of the tension is 3:1

Answer 2

Answer:

Upward acceleration=T1=m(g+a)

Downward acceleration=T2=m(g-a)

T1/T2=g+a/g-a

=9.8+4.9/9.8-4.9=3:1

Explanation: