Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

show step by step 1) a 150g bullet is fired from a rifle with a barrel of length

ID: 2089718 • Letter: S

Question

show step by step 1) a 150g bullet is fired from a rifle with a barrel of length 65cm the bullet starts from rest at one end of the barrel and experiences a position dependent force due to the expanding gases given by... F(x)= 15,000+10,000x-25,000x^2 in newtons with x in meters. a) calculate the work done on the bullet by this force over the length of the barrel. b) assuming that this is only force doing work on the bullet ( neglect friction) find the speed of the bullet as it leaves the rifle.

Explanation / Answer

a) work done = integral of F.ds = integ)ral of (65-0){ (15,000+10,000x-25,000x^2).dx}

= (65-0) (15000x +5000x^2 - 25000/3x^3) = 9596.8 J

b) work done = change in kinetic energy

9596.8 = 1/2 m(vf^2 - 0)

Vf = 357.7 m/s