From a rifle of mass 4kg a bullet of mass 50g is fired with an initial velocity of `35 ms^-1` calculate the initial recoil velocity of the rifle.

Explanation

To solve the problem of finding the initial recoil velocity of the rifle when a bullet is fired, we will use the principle of conservation of linear momentum. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Conservation of Momentum
The law of conservation of momentum states that the total momentum of a closed system before an event must equal the total momentum after the event. In this case, before the bullet is fired, both the rifle and the bullet are at rest, so their total initial momentum is zero.

### Step 2: Define the Variables
- Mass of the rifle (M_r) = 4 kg
- Mass of the bullet (M_b) = 50 g = 0.05 kg (convert grams to kilograms)
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