Question

A uniform rod of length L and mass 2.0 kg is made to rest on two measuring scales at its two ends. A uniform block of mass 2.8 kg is placed on the rod at a distance of \(\frac{L}{4}\) from its left end. The force experienced by the measuring scale on the right end is

(a) 10 N 

(b) 15 N 

(c) 17 N 

(d) 19 N

Answer 1

Answer is (c) 17 N

As the rod is at rest, so torque about the left end should be zero, i.e.

⇒ F = 7 + 10 = 17 N