Question

- A uniform rod is 4m long and weights 10kg.
If it is supported on a knife edge at one meter
from the end, what weight placed at that end
keeps the rod horizontal.
1) 8kg 2) 10kg 3) 12kg 4) 15kg​

Answer 1

The weight placed at other end to keep the rod horizontal will also be 10 Kg.

Explanation:

We are given that:

• Length of rod = 4 m
• Weight = 10 Kg

Solution:

Now apply the formula of torque balance:

τ x = w x τ

Torque gets cancelled on both sides.

Therefore;

x =  w

Since w = 10 Kg

Hence x = 10 Kg

Thus the weight placed at other end to keep the rod horizontal will also be 10 Kg.

Answer 2

Answer:

10 kg

Explanation:

mg(1)=10×1×(g)

m=10 kg