Question

A uniform 2-metre scale has weights 5gf and 30gf at its ends. If it

balances 50cm from one end, what is the weight of the rod?​

Answer 1

There is given :-

Rod if 200cm

1 mass of 30 gram

1 mass of. 5 gram

rod's mass is to find

it balance at 50 cm from one end this means

at that point net torque is balanced

torque = distance of force from point if application × Force

T = r × F

so lets balance clockwise and anticlockwise torque at 50 cm from 30 gram

torque clockwise = 50 × 3

torque anti clockwise = 50 × 10m + 150 × 0.5

equating above 2 equations

on solving we get mass of rod as 3÷20

so

weight of rod is mass ×10

weight of rod = 3÷2 = 1.5 gram