Question

a man of mass 80 kg standa on a lift going upward at the speed of 2 m/s. what is the weight of man on the lift. take g=10m/s

Answer 1

Mass(m) = 80 kg 

speed(v) = 2m/s 

acceleration due to gravity (g) = 20m/s

weight(w)=?

w = mg

In this particular case 

N= mg + ma 

mg = N - ma 

a =0 (uniform velocity)

so mg = N 
80 x 10 = N 

N (normal Reaction) = 800 N