passwella.
Menu

JAMB Physics 2003 Question 11

Question 11

Equilibrium of Forces

A 90cm uniform lever has a load of 30N suspended at 15cm from one of its ends. If the fulcrum is at the centre of gravity, the force that must be applied at its other end to keep it in horizontal equilibrium is

  1. A.15N
  2. B.20N
  3. C.30N
  4. D.60N
Show the answer and explanation

Answer: B (20N)

Explanation

Fulcrum at 45 cm. Moments: 30 × (45 − 15) = F × 45, so F = 900/45 = 20 N.