Question

A man of mass $60\text{kg}$ records his weight on a weighing machine placed inside a lift. The ratio of weight of man recorded when lift ascends up with a uniform speed of $2\text{m/s}$ to when it is descending down with a uniform speed of $4\text{m/s}$ will be:

• A. $0.5$
• B. $1$
• C. $2$
• D. $4$

Answer 1

Answer: (B)

$1$

A force acts on a body when it is accelerating. Whether the lift moves with $2m/s$ or $4m/s$, no force acts on the man as long as the speed is constant. Thus in both the cases the measured weight is equal to $60kg$.