Question

3. If three coplanar forces acting on a rigid body keep it in equilibrium, they
must be
(a)parallel
(b)perpendicular
(c)concurrent
(d)either (a) or (C)


4. When a rod is resting on a smooth peg, the reaction of the peg on the rod
is to the rod.
(a)parallel
perpendicular
(c)equal
(d)none of these​

Answer 1

Step-by-step explanation:

3)(b) because component of force will give same value of force as sin(90)=1

4)

Answer 2

Vector and Forces

3. (c)concurrent

If three coplanar forces acting on a rigid body keep it in equilibrium, they must be concurrent. These concurrent forces can be collinear or non- collinear.

Collinear forces are those forces whose line of action lies on the same line.

4. (b)perpendicular

When a rod is resting on a smooth peg, the reaction of the peg on the rod is perpendicular to the rod.