Man in an Accelerating Lift – Rankers Physics
Topic: Laws of Motion
Subtopic: Pseudo Force

Man in an Accelerating Lift

Assertion (A): A man standing in a lift which is moving upward, will feel his weight to be greater than when the lift was at rest.
Reason (R): If the acceleration of the lift is 'a' upward, then the man of mass m shall feel his weight to be equal to normal reaction (N) exerted by the lift given by \(N = m(g - a)\) (where \(g\) is acceleration due to gravity)
 
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Solution:

When a lift accelerates upwards, apparent weight is \(N = m(g + a)\), which is greater than \(mg\). So (A) is true. Reason (R) provides the formula for downward acceleration, thus (R) is false.

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