A man of mass 60 kg is riding in a lift. The weight of the man, when the lift is accelerating upwards and downwards at 2 $ms^{-2}$ , are respectively . (Taking g = 10 $ms^{-2})$

When the lift is accelerating upwards with a constant acceleration a, then weight, w = m(g + a) $ \, \, \, \, \, \, \, = 60 (10+2) = 60 \times 12$ $ \, \, \, \, \, \, \, \, = 720N$ When the lift is accelerating downwards at the rate a, then weight, w' = m(g - a) $ \, \, \, \, \, \, \, \, =60(10-2)=60 \times 8$ $ \, \, \, \, \, \, \, \, =480N$

A man of mass 60 kg is riding in a lift. The weigh

Notes on laws of motion

Concepts Used:

Laws of Motion

The laws of motion, which are the keystone of classical mechanics, are three statements that defined the relationships between the forces acting on a body and its motion. They were first disclosed by English physicist and mathematician Isaac Newton.

Newton’s First Law of Motion

Newton’s 1^st law states that a body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it.

Newton’s Second Law of Motion

Newton's 2^nd law of motion deals with the relation between force and acceleration. According to the second law of motion, the acceleration of an object as built by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Newton’s Third Law of Motion

Newton's 3^rd law of motion states when a body applies a force on another body that there is an equal and opposite reaction for every action.

A man of mass 60 kg is riding in a lift. The weight of the man, when the lift is accelerating upwards and downwards at 2 $ms^{-2}$, are respectively . (Taking g = 10 $ms^{-2})$

The Correct Option is A

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