A100 kg person stands on a scale in an elevator What is the

A100 kg person stands on a scale in an elevator. What is the reading on the scale (in Newtons) for each of the below scenarios?

Solution

A) Applying Fnet = m a

N - mg = ma

N = ma + mg = 100 ( 2 + 9.81) =1181 N

(B) mg - N = ma

N = mg - ma = 100 (9.81 - 2) = 781 N

(c) now a = 0

hence N = mg = 100 x 9.81 = 981 N

(d) N = 100 x 9.81 = 981 N