Question

15. A uniform metre rule of weight 10 gf is pivoted at its
0 mark.
(i) What moment of force depresses the rule ?
(ii) How can it be made horizontal by applying a least force?

Please answer correctly, all wrong answers will be reported. ​

Answer 1

Answer:

i 500 gfcm

ii by appling 10gf upward force at 50cm mark

Answer 2

Anticlockwise moment = 10 gf × 50 cm = 500 gf cm

According to principle of moment:

Anticlockwise moment = Clockwise moment

10 gf × 50 cm = W × 100 cm

So, W = (10 gf × 50 cm) / 100 cm

= 5 gf

Rule can be made horizontal by applying a force 5 gf upwards at the 100 cm mark.