Question:
Krishan applies a force of 15 kgf using a spanner of 30 cm to unlock a nut. If Arjun wants to unlock the same nut with a force of only 5 kgf, what should be the length of Arjun's spanner? Take 1 kgf = 10 N for calculations.
Answer:
Krishan applies a Force (F) = 15 kgf = 15 x 10 N = 150 N
Perpendicular distance (d) = 30 cm = 30/100 m = 0.3 m
Moment of force = F x d = 150 × 0.3 = 45 Nm
Arjun applies a Force (F) = 5 kgf = 5 x 10 N = 50 N
Perpendicular distance (d) = ?
Moment of force = 45 Nm
Moment of force = F x d
45 = 50 x d
d = 45/50 = 0.9 m = 90 cm