Question

Hola friend !

Explain the term motion in a lift ( elevator ) ?​

Answer 1

Explanation:

motion in a lift elevator when a body of mass m is placed on the floor of a lift it is subject of two forces1}gravitational pull

Answer 2

Answer:

motion in a lift (Elevator)

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when a body of mass m is placed on the floor of a lift, it is subject to two forces :

(1) gravitational pull mg

(2) the reaction R exerted by the floor

The reaction R is the measure of the apparent weight of the body.

Let us consider the following cases :

(1) The lift is stationary or moves with constant speed - since the acceleration is zero, so

R - mg = 0

R = mg

(2) The lift ascends with acceleration 'a' - in this case equation of motion is

R - mg = ma

R = mg + ma

the apparent weight of the body in this case is increased.

(3) The lift descends with acceleration 'a' - Now the equation of motion is

mg - R = ma

R = mg - ma

that is, the apparent weight is now decreased.