Question

Four equal and parallel forces are acting on a rod of length $100cm$, as shown in figure, at distances of $20cm,40cm$ $60cm$ and $80cm$ respectively from one end of the rod Under the influence of these forces, the rod (neglecting its weight)

• A. experiences no torque
• B. experiences torque
• C. experiences a linear motion
• D. experiences torque and also a linear motion

Answer 1

Answer: (B)

Since, upward forces on the rod are equal to downward forces, hence, the resultant force on the rod is zero and there is no linear motion. Moment of forces about one end of rod
$=-F\times 20+F\times 40-F\times 60+F\times 80=F\times 40$
As it is not zero, hence the torque acts on the rod.