A 100 g bullet is fired from a rifle that has a 0.60 m long barrel.

Question

The origin of the movement is considered the place where the bullet begins to move, the force (in newtons) exerted on the bullet due to the expansion of the gas is 15000 + 10000x - 25000x2 where the unit of x is expressed in meters. Determine the work done by the gas on the bullet when it runs through the rifle's barrel.

Answer 1

Use dW = Fdx and so W= ∫₀^.6(15000+10000x -25000x²)dx. So W= ( 15000x + 10000x²/2 - 25000x³/3)₀^.6. This gives W= 9000 + 1800 - 388.8 N-m = 10.4 kN-m for the work done.