Question

A metre rule is pivoted at it's centre.A glass block is hanged from one end and the rule is balanced horizontally by hanging masses of 100g and 50g at 60cm and 80cm marks respectively.calculate the mass of the glass block

Answer 1

pivot at 50 cm
m * 50 cm = 100* 10 + 50 * 30
m = 20 + 30 = 50 grams