Question

A uniform half metre rule can be balanced at the
29.0 cm mark when a mass 20 g is hung from its one
end.
(a) Draw a diagram of the arrangement.
(b) Find the mass of the half metre rule.
(c) In which direction would the balancing point
shift if 20 g mass is shifted inside from its one
end ?​

Answer 1

Answer:

m = 105g

Explanation:

A uniform rule has same distribution of mass through it length , so its length Mg will acts at its middle point which is at 25cm .

The weight Mg produces anticlockwise moment at point o . In order to balance 20 g (0.02kg) weight is tied at 50 cm mark which generates clockwise moment

anticlockwise moment=clockwise moment

mg=(29-25) = 0.02 g (50-29)

mg=21(0.02)/4

mg= 0.105kg ( convert to g)

mg= 105g