Laws Of Motion Question 194
Question: A man is standing on a weighing machine placed in a lift. When stationary his weight is recorded as 40 kg. If the lift is accelerated upwards with an acceleration of $ 2m/s^{2} $ , then the weight recorded in the machine will be $ (g=10m/s^{2}) $ [MP PMT 1994]
Options:
A) 32 kg
B) 40 kg
C) 42 kg
D) 48 kg
Show Answer
Answer:
Correct Answer: D
Solution:
In stationary lift man weighs 40 kg i.e. 400 N. When lift accelerates upward it’s apparent weight $ =m(g+a) $
$ =40(10+2)=480\ N $ i.e. 48 kg For the clarity of concepts in this problem kg-wt can be used in place of kg.