A projectile of mass `50 kg` is shot vertically upwards with an initial velocity of `100 m//s`. After `5 s`, it explodes into two fragments, one of which having a mass of `20 kg` travels vertically up with a velocity of `150 m//s`:
a. What is the velocity of the other fragment that instant?
b.Calculate the sum of rnornenta of fragment `3s` after the explosion. What would have been the momentum of the projectile at this instant if there had been no explosion?

Explanation

To solve the problem step by step, we will break it down into parts as outlined in the question.

### Given Data:
- Mass of the projectile, \( m = 50 \, \text{kg} \)
- Initial velocity, \( u = 100 \, \text{m/s} \)
- Time before explosion, \( t = 5 \, \text{s} \)
- Mass of the first fragment, \( m_1 = 20 \, \text{kg} \)
- Velocity of the first fragment after explosion, \( v_1 = 150 \, \text{m/s} \)
...