Question

In order to rotate a bar pivoted at its midpoint, we need to apply ______.

Options

• a large force at any point on the bar

• a small force exactly at the midpoint where it is pivoted

• two unequal forces at the two ends, but in the same direction

• two equal forces at the two ends, but in opposite directions

Answer 1

In order to rotate a bar pivoted at its midpoint, we need to apply two equal forces at the two ends, but in opposite directions.

Explanation:

Two equal and opposite parallel forces acting at different points form a couple. A couple produces a turning effect and rotates the bar about its pivot.