Question

question 24 of 26
a rifle is used during the biathlon event in the olympics. the shooter lies still on the ground while he shoots the rifle. the rifle has a mass of 3 kg and the bullet has a mass of 0.015 kg. after it is shot, the bullet travels at a speed of 450 m/s. what is the total momentum of the rifle - bullet system before the bullet is shot?

a. 6.75 kg·m/s
b. 1365 kg·m/s
c. 0 kg·m/s
d. 1350 kg·m/s

Explanation:

Step1: Recall momentum formula

Momentum $p = mv$, where $m$ is mass and $v$ is velocity.

Step2: Analyze initial - state velocities

Before the bullet is shot, both the rifle and the bullet are at rest. So, the initial velocity of the rifle $v_{r - initial}=0$ m/s and the initial velocity of the bullet $v_{b - initial}=0$ m/s.

Step3: Calculate total initial momentum

The total momentum of the rifle - bullet system $p_{total}=m_{r}v_{r - initial}+m_{b}v_{b - initial}$, where $m_{r} = 3$ kg (mass of rifle) and $m_{b}=0.015$ kg (mass of bullet). Substituting the values, we get $p_{total}=3\times0 + 0.015\times0=0$ kg·m/s.

Answer:

C. 0 kg·m/s