2 questions: Force of bullet and car

[mikex213]

Homework Statement

(1)A 5g bullet leaves the muzzle of a rifle with a speed of v=320m/s. what force (assumed constant) is exerted on the bullet while it is traveling down the 0.82m-long barrel of the rifle?

(2)Two forces are applied to a car in an effort to move it. what is the resultant of these two forces? if the car has a mass of 3000kg, what acceleration does it have? ignore friction.
The car is facing 90degree position, 1st force is 60degrees at 400N, 2nd force is at 100degrees at 450N.

Homework Equations

d=vt
a=v/t
f=ma

The Attempt at a Solution

(1) i tried, d=vt, .82=320m/s*t, t=.003s
a=v/t, a=320m/s / .003s, a=124800m/s^2
f=ma, F= .005kg*124800m/s^2, F=624N

(2) i don't know how to do this one..

 

[The legend]

for 2) draw the free body diagram first(and post it here) and see if you get an idea.

 

[Redbelly98]

Welcome to Physics Forums.

The Attempt at a Solution

(1) i tried, d=vt, .82=320m/s*t, t=.003s

The v in that formula should be v_average. However, you have used v_final.

What is v_average, given that v_initial is zero and v_final is 320 m/s/

a=v/t, a=320m/s / .003s, a=124800m/s^2
f=ma, F= .005kg*124800m/s^2, F=624N

The rest of your work is correct, you just need to get the correct value for t first.