It should be the 3rd one but idk for sure. if its not then its the 3rd one
Answer:
The recoil velocity of the gun is
and is pointing in opposite direction to the velocity of the bullet.
Step-by-step explanation:
Use conservation of linear momentum, which states that the momentum of the bullet (product of the bullet's mass times its speed) should equal in absolute value the momentum of the recoiling gun (its mass times its recoil velocity).
We also write the mass of the bullet in the same units as the mass of the gun (for example kilograms). Mass of the bullet = 0.010 kg
In mathematical terms, we have:

An exponent is the number or value being raised to a power.
Answer: Pressure(t) = 5mP*sin(191.08*t)
Step-by-step explanation:
The information we have:
Maximum pressure P = 5 mP
frequency = 1200Hz
Period = 1/frequency = (1/1200) seconds
when t = 0, P = 0, so we should use a sin function (because sin(0) = 0)
Then we can write this as:
Pressure(t) = P*sin(c*t)
where t is time in secnds, P is the maximum pressure 5mP, and c is a constant that depends on the period.
Pressure(t) = 5*sin(c*t)
knowing that the period is 1/1200 seconds, we have that:
c*1/1200 s = 2*3.14
c = 1200/(2*3.14) 1/s= 600/3.14 1/s
Our function is
Pressure(t) = 5mP*sin(191.08*t)