Final answer:
The recoil velocity of the rifle can be calculated using the law of conservation of momentum.
Step-by-step explanation:
The recoil velocity of a rifle can be determined using the law of conservation of momentum. According to this law, the total momentum before the bullet is fired is equal to the total momentum after the bullet is fired. The momentum of an object can be calculated by multiplying its mass by its velocity. In this case, the mass of the rifle is 3.0 kg and the mass of the bullet is 0.025 kg.
Before the bullet is fired, the total momentum is zero since both the rifle and bullet are at rest. After the bullet is fired, the momentum of the bullet is 0.025 kg * 450 m/s = 11.25 kg·m/s. To find the recoil velocity of the rifle, we can use the equation:
0 = (3.0 kg + 0.025 kg) * Vrecoil
Solving for the recoil velocity, we get:
Vrecoil = - (0.025 kg * 450 m/s) / 3.0 kg = -0.375 m/s
The negative sign indicates that the rifle recoils in the opposite direction of the bullet's motion.