Three forces acting on a body are in equilibrium. When drawn head to tail they must

  • A. lie along one straight line
  • B. form a closed triangle
  • C. all be equal in magnitude
  • D. be mutually perpendicular

Explanation

A zero resultant means the head of the last vector coincides with the tail of the first, so the three vectors close a triangle. This triangle of forces lets an unknown force be found by scale drawing or by the sine rule. The three need not be equal, and they cannot be collinear unless two of them point the same way.

Related questions