What will be the weight of a man of mass 60kg standing in a lift if the lift is descending vertically at 3ms\(^2\)?
A
780N
B
546N
C
660N
D
420N
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
The man's weight = T - ma
mass = 60kg, a = 3ms\(^2\)
The man's weight = m(g - a) = 60(10 - 3) = 60 x 7 = 420N
Source: WAEC / JAMB / NECO Classroom Archive (Record #70485)