A shell of mass 200g is fired by a gun of mass 100kg. If the muzzle speed of the shell is `80ms^(-1)`, then the recoil speed of the gun is

Explanation

To solve the problem of finding the recoil speed of the gun when a shell is fired, we will use the principle of conservation of momentum. Here’s a step-by-step 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 shell is fired, both the gun and shell are at rest, so the total initial momentum is zero.

### Step 2: Write the Initial Momentum
Before firing, the momentum of the system (gun + shell) is:
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