Question

10 m)
2. A woman weighing 50 kgf stands on a weighing
machine placed in a lift. What will be the reading of
the machine, when the lift is (i) moving upwards
with a uniform velocity of 5 ms and (ii) moving
downwards with a uniform acceleration of 1 ms??
[Punjab 91
[Ans. (i) 500 N (ii) 450 N
Take g = 10 ms?​

Answer 1

Answer:

500 N & 450 N

Explanation:

(i)

When the left is moving with uniform velocity, the weight of person inside the lift remains same.

So,

F = mg

= 50 kg × 10 m/s²

= 500 N

(ii)

When lift is moving downwards with an acceleration "a"

F = m(g - a)

= 50 kg × (10 m/s² - 1 m/s²)

= 50 kg × 9 m/s²

= 450 N