Standing on a scale on an elevator is a man of mass 140kg. a) what is the reading of the scale if the elevator moves up at 5 m/s. b) moves down at 5m/s c) accelerated up at 2m/s^2 d) accelerates down at 2m/s^2?
for a) and b) would I use N=m(g+a) but when I did I got the same answer would that be right since a=a in a) and b). For c) and d) I would use the same equation as a) and b) but the only difference would be the acceleration for c) which would be positive 2 and d) would be negative 2.
You mean a = g, in problems a) and b),? Yes that's right. And the answer for c) and d) also correct.
It's still instructive to actually derive the formula N=m(g+a)...