Two blocks of msses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

Explanation

To solve the problem, we need to find out how far the second block (30 kg) should be moved in order to raise the center of mass of the system by 1 cm after the first block (10 kg) is raised by 7 cm.

### Step-by-Step Solution:

1. **Identify the masses and displacements:**
- Mass of block 1, \( m_1 = 10 \, \text{kg} \)
- Mass of block 2, \( m_2 = 30 \, \text{kg} \)
- Displacement of block 1, \( s_1 = 7 \, \text{cm} \) (upward)
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