An elevator has an upward acceleration of 1 m/s² What will be the force transmitted to the floor of the elevator by a man of weight 500 N travelling in the elevator? [g = 10 m/s²]

Question

Question

This question was previously asked in

APPSC Lecturer (Polytechnic Colleges) Held on March 2020

Answer 1

Concept:

Inertial Frame of Reference	Non-Inertial Frame of reference
The frame of reference either at rest or moving with constant velocity is known as an inertial frame of reference.	The frame of reference accelerated to an inertial frame of reference is known as a non-inertial frame of reference.
Newton’s laws are applicable in an inertial frame of reference.	Newton’s laws are not applicable in a non-inertial frame of reference. To apply newton’s law a pseudo force is applied in the opposite direction of acceleration.
Ex. Earth, Bus moving with uniform velocity.	Ex. Accelerated or decelerated bus

Calculation:

Given:

F1 Ashik Madhu 14.08.20 D16

Upward acceleration of elevator a = 1 m/s²

Weight of man W = 500 N

^{\(Mass~of~man,m = \frac{{500}}{{10}} = 50~kg\)}

As the lift is a non-inertial frame of reference moving upward with acceleration ‘a’ we apply pseudo force ‘ ma’ in the downward direction.

Considering FBD of man,

N = mg + ma

N = m (g + a)

N = 50 × (10 + 1) = 550 N