Question

(AMU 2010)
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 (take,
g=10 ms -2):
(a) 720 N and 480 N
(b) 480 N and 720 N
(c) 600 N and 600 N
(d) none to these​

Answer 1

Answer:

Option (a) 720 N and 480 N

Explanation:

m = 60 kg

g = 10 m/s^2

a = 2 m/s^2

Now when the lift is moving upwards,

The apparent weight, W_up = m (g + a) = 60 (10+2) = 60 x 12 = 720 N

When the lift is moving downwards,

The apparent weight becomes, W_down = m (g - a) = 60 (10-2) = 60 x 8 = 480 N

So option (a) 720 N and 480 N is correct.