Question

a uniform half metre rule can be balanced at the 29.0 cm mark when a mass 20g is hung from its one end .find the mass of the half metre rule

Answer 1

Hello Dear.

Here is the answer---

•¶ Refers to the attachment for the Question.

Let the weight of the half metre rule be x gf and it acts at the 25 cm mark (centre of gravity).

Now,
•Acticlockwise moment = x * 4
•Clockwise moment = 20 * 21

In equilibrium,
Anticlockwise moment = Clockwise moment
•4x = 20*21
x = 105 gf.

Thus, the weight of the metre rule is 105 gf.

•We know, one gf is the force acting on the body of mass 1 grams, thus mass of the body is 105 grams.

°°°°°°°°°°°=°°°°°°°°°°°°°

•Hope it helps.•

Have a Marvelous Day ☺️

Answer 2

hope it helps ...it s correct