A body weighing 80N stands in an elevator that is about to move. The force exerted by floor on the body as the elevator moves upward with an acceleration of 5 ms-2 is
[g = 10ms-2]
A
40 N
B
80 N
C
120 N
D
160 N
Verified Correct Answer: C.
Physical Principles & Numerical Solution
W = Mg
man's weight = 80N then his mass = \(\frac{80}{10}\) = 8kg
T = Mg + Ma = M( g + a) = 8(10 + 5) = 8 x 15 = 120N.
Source: Myschool Past Questions Archive (Record #9671)