Answer:
4 m/s
Explanation:
Momentum is defined as:

where
m is the mass of the object
v is its velocity
For the object in this problem, we know:
p = 200 kg m/s is the momentum
m = 50 kg is the mass
Solving for the velocity, we find:

The velocity of the submarine immediately after firing the missile is 0.0104 m/s
Explanation:
Mass of the submarine M=50 tonne=
Mass of the missile m=40 kg
velocity of the missile v= 13m/s
we have to calculate the velocity of the submarine after firing
This is the recoil velocity and its expression is derived from the law of conservation of momentum
recoil velocity of the submarine

The question is a little confusing. An electromagnetic wave is radiation. One doesn’t emit the other. Take another look at the question and write it again please.
A Cyclone is a hurricane.