Question

A physical balance has its arm of lwngth 60cm and 40cm what weight kept on pan of longer arm will balance the object of wieght 100 gf kept on other pan ? (chapter :Froce)

Answer 1

m1r1 = m2r2

m2 = m1r1 / r2
= 100 * 40 / 60
= 66.67 gf

A weight of 66.67 gf will balance the object of weight 100 gf kept on other pan.

Answer 2

Answer:

The weight of 66.67 gf will balance the weight of 100 gf.  

Explanation:

The physical balance has arm length of 60 and 40 cm respectively, so the balance weight for 100 gf  is given by –

Given – Arm length l1 = 40 cm

    Arm length l2 = 60cm

Weight to be balanced w1 = 100 gf

Weight to be balanced by, w2 = w

Conservation of mass is used to solve this equation

$\begin{array}{l}{\frac{w_{1}}{l_{2}}=\frac{w_{2}}{l_{2}}} \\ {w_{1} l_{1}=w_{2} l_{2}} \\ {100 \times 40=w_{2} l_{2}} \\ {w_{2}=\frac{4000}{60}} \\ {w_{2}=\frac{400}{6}}\end{array}$

$w_{2}=66.67 \mathrm{gf}$

The weight of 66.67 gf will balance the weight of 100 gf.