Question

A 75 g bullet is fired from a rifle having a barrel 0.650 m long. Assuming the origin is placed where the bullet begins to move, the force (in newtons) exerted by the expanding gas on the bullet is 14000 + 10000x - 21000x2, where x is in meters.

Answer 1

Answer:

7557.875 J

Explanation:

Assumimg we need to find work done by the bullet on the gas

The work is found by integrating force over distance

W= $W=\int_{x_i}^{x_f}F.ds$

For the force in this problem we have

$W=\int_{0}^{0.65}14000 + 10000x - 21000x^2.ds$

= $[14000x+10000x^2-21000x^3]_{0}^{0.65}$

=7557.875 J