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
waec 2016furthermathematics

The correct answer is D. 840N

\(\text{Net force = Upward force - weight}\)

\(ma = F - mg  \implies F = ma + mg \)

\(F = (80 \times 10) + (80 \times 0.5) = 800 + 40 = 840N\)

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