Final answer:
The recoil velocity of the rifle would be approximately zero.
Step-by-step explanation:
To calculate the recoil velocity of the rifle, we can use the principle of conservation of momentum. The momentum of the bullet before firing is given by the product of its mass and velocity. Since the rifle weighs 100 times as much as the bullet, the change in its velocity will be much smaller compared to the bullet's velocity. So, we can neglect the change in the rifle's velocity. Therefore, the recoil velocity of the rifle is approximately zero in this case.