Question

Two blocks (m1 = 40 kg, m2 = 30 kg) are connected by a compressed spring, and are initially at rest. The spring breaks and the two objects fly apart from one another. If the speed of the first block is 15 m/s, what is the speed of the second block?

Answer 1

Speed of second block will be 20 m /sec in opposite direction

Step-by-step explanation:

We have given the mass of two blocks
`m_1=40kg` and
`m_2=30kg`

As both the blocks are initially at rest so
`u_1=0m/sec\ and\ u_2=0m/sec`

Speed of first block
`v_1=15m/sec`

We have to find the speed of second block, that is
`v_2`

From momentum conservation we know that

`m_1u_1+m_2u_2=m_1v_1+m_2v_2`

`40* 0+30* 0=40* 15+30* v_2`

`v_2=-20m/sec`

So speed of second block will be 20 m /sec in opposite direction.