A man of mass 80kg stands in a lift. If the lift moves upwards with acceleration 0.5(ms^{-2}), calculate the reaction from the floor of the lift on the man. ([g = 10ms^{-2}])
-
A.
760N -
B.
800N -
C.
805N -
D.
840N
Correct Answer: Option D
Explanation
(text{Net force = Upward force – weight})
(ma = F – mg implies F = ma + mg )
(F = (80 times 10) + (80 times 0.5) = 800 + 40 = 840N)