Question

A lift is descending with an acceleration or 4.9 m/sec2
The apparent weight of a person of 60 kg mass will be-
(A) 90 kg wt
(B) 60 kg wt.
(C) 30 kg wt.
(D) 0 kg wt.​

Answer 1

Given,

weight of man =60kg

downwards acceleration =2m/s2

Now, when lift moves downwards

w2=m(g−a)

=60(10−2)m/s2

=480N

Again, w1=mg

∴w1=60×10=600N

Now, change percentage of apparent weight

=w1w1−w2×100

600600−480×100=20%

∴ change is 20%