WAEC - Further Mathematics (2015 - No. 24)
A mass of 75kg is placed on a lift. Find the force exerted by the floor of the lift on the mass when the lift is moving up with constant velocity. \([g = 9.8ms^{-2}]\)
750N
745N
735N
98N
설명
Net force = Upward force - weight
\(ma = F - mg\)
With constant velocity, acceleration = 0, therefore, ma = 0
\(\therefore F = mg = 75 \times 9.8 = 735N\).