Question

A body of mass m is placed on an elevator.when the elevator accelerates upward and downward with the same magnitude 'a' ,the corresponding normal reactions on the body are N1 and N2
(a)a=N1+N2/2m
(b)a=N1N2/2m
(c)a=N1-N2/2m
(d)a=2N1-N2/2m

Answer 1

Answer:

R= Normal reaction by the elevator floor on the passenger

a= Acceleration of elevator upward

mg= Weight of passenger

Using Newton's 2nd law,

R−mg=ma

⇒R=m(g+a)

Force by the passenger on the elevator floor is same as R by Newton's 3rd law.