Question

Question #3ef90

Answer 1

I think the answer is b, 39 cm.

Explanation:

The clockwise and anti clockwise moments have to balance. The fulcrum is at the 45cm mark. The weight of the rod is 0.6N and we can reasonably assume that the centre of gravity is at the 50 cm mark. Hence this acts 5cm from the fulcrum with a moment of `5*0.6N=3Ncm`. The 0.5N weight will need to be placed at a distance,d, on the other side of the fulcrum. Hence `0.5*d=3` so d=6cm. A distance of 6cm from the fulcrum will be at the 39cm mark (45-6).