Laws Of Motion Question 272
Question: A mass of 1 kg is suspended by a thread. It is
(i) lifted up with an acceleration $ 4.9m/s^{2} $ , (ii) Lowered with an acceleration$ 4.9m/s^{2} $ . The ratio of the tensions is
Options:
A) $ 3:1 $
B) $ 1:2 $
C) $ 1:3 $
D) $ 2:1 $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] In case (i) we have $ T _{1}-( 1\times g )=1\times 4.9 $
$ \Rightarrow T _{1}=9.8+4.9=14.7\text{ N} $ In case (ii) $ ,1\times g-T _{2}=1\times 4.9 $
$ \Rightarrow T _{2}=9.8-4.9=4.9\text{ N}\therefore \frac{T _{1}}{T _{2}}=\frac{14.7}{4.9}=\frac{3}{1} $
