Question

A man of 80 kg mass stands on a weighting machine in a lift which is moving upwards with a uniform speed of 5m/s. The reading of the weighing machine will be. (Take g = 10 m/s² ) 

(1) zero 

(2) 400N 

(3) 800N 

(4) 1200N

Answer 1

(3) 800N

V = constant, a = 0, m = 80 kg 

T = mg = 800 N