Question

Two forces which form a couple can't be replaced by a single equivalent force. Is that statement true ???​

Answer 1

Yes, it is true that two forces which form a couple can't be replaced by a single equivalent force.

• From the definition of couple we came to know that couple is a pair of two parallel forces which acts in the opposite directions of each other.
• Now,a couple can only produce rotational motion in a body and translational motion cannot be produced by a couple.
• On the other hand, a single force will always produce translational motion in a body.
• So, it's clear that the final result by a couple and a single force is completely different from each other.
• That's why, a single equivalent force cannot replace a couple.