Physics

Physics

Problem

Three forces, each of equal magnitude FF, act simultaneously on a particle. For the particle to remain in equilibrium, the angle between any two successive forces must be a) 90∘90^{\circ} b) 180∘180^{\circ} c) 120∘120^{\circ} d) 60∘60^{\circ}
Intuitive explanation

The key insight is that equilibrium means the net force is zero—so all forces must sum to a vector of magnitude zero. With three equal-magnitude forces, think about how they'd need to be arranged in space to perfectly cancel each other out. Symmetry is your friend here: if they're evenly spaced around a circle, each one can balance the other two. Work out what angle that spacing requires.

Intuitive explanation

The key insight is that equilibrium means the net force is zero—so all forces must sum to a vector of magnitude zero. With three equal-magnitude forces, think about how they'd need to be arranged in space to perfectly cancel each other out. Symmetry is your friend here: if they're evenly spaced around a circle, each one can balance the other two. Work out what angle that spacing requires.

Browse the problem library