The conservation of momentum states that the total momentum in a system is constant if there is no external force acting on the system. The total momentum in the gun bullet system is 0 so it must stay that way.
The momentum of the bullet is mv = 0.015*500=7.5
The momentum of the gun must be the same to keep the total momentum of the system equal to zero, so we know that p = 7.5 for the gun.
Substituting this in we get:
7.5=3.1x
x=7.5/3.1
x=2.42
So the speed of the gun is 2.4m/s.
Answer:

Explanation:
If the weight is a linear function of the amount of fuel, the following correlation is fulfilled :

we solve the equation:

Answer:
Somatic motor neurons originate in the central nervous system, project their axons to skeletal muscles (such as the muscles of the limbs, abdominal, and intercostal muscles), which are involved in locomotion.
Explanation:
Muscles move on commands from the brain. Single nerve cells in the spinal cord, called motor neurons, are the only way the brain connects to muscles. When a motor neuron inside the spinal cord fires, an impulse goes out from it to the muscles on a long, very thin extension of that single cell called an axon.
Answer:
ωf = 0.16 rad/s
Explanation:
Moment of inertia of the child = mr² = 20(1.6²) = 51.2 kg•m²
Moment of Inertia of the MGR = ½mr² = ½(180)1.6² = 230.4 kg•m²
(ASSUMING it is a uniform disk)
Initial angular momentum of the child = Iω = I(v/r) = 51.2(1.4/1.6) = 44.8 kg•m²/s
Conservation of angular momentum
44.8 = (51.2 + 230.4)ωf
ωf = 0.15909090...