Question

Two blocks of mass $10$ kg and $30$ kg are placed along a vertical line the first block of mass $10$ kg is raised through a height of $7$ cm by what distance should the second block of mass $30$

Answer 1

Two masses m₁ and m₂ are kept in a vertical line.

m₁=10 kg m₂= 30 kg

y₁ = 7cm y₂ = ?

The centre of mass is raised by 1 cm.

Centre of mass = (m₁y₁+m₂y₂) / (m₁+m₂)

1 = (10x7₁+30y₂) / (10+30)

1 = (70+30y₂) / 40

40 = 70+30y₂

30y₂ = -30

y₂ = -1

So , m₂ = 30 kg body should be displaced 1 cm downward so , as to raise the centre of mass through 1 cm.