Question

A man will weigh more when

• A. lift accelerates upwards
• B. lift accelerates downwards
• C. lift descends freely
• D. lift is going down

Answer 1

Answer: (A)

lift accelerates upwards

Answer 2

When a lift accelerates upwards with uniform acceleration a $\therefore$ Apparent weight of man $R=m(g+a)$ When a lift accelerates downwards with uniform acceleration a $\therefore$ Apparent weight of man $R=m (g-a)$ When a lift descends freely $\therefore$ Apparent weight of man $R=m(g-g)=0$ [since $a=g]$ When a lift is going down (without acceleration), $\therefore$ Apparent weight of man $R=m(g-0)=mg$ [since $a=0]$ Hence, a man weigh more, when lift accelerates upwards