A wooden boxcar is moving along a straight railroad track at speed v1. A sniper fires a bullet (initial speed v2) at it from a high-powered rifle. The bullet passes though both lengthwise walls of the car, its entrance and exit holes being exactly opposite each as viewed from within the car. From what direction, relative to the track, is the bullet fired? Assume that the bullet is not deflected upon entering the car, but that its speed decreases by 20%. Take v1=85km/hr and v2 = 650 m/s.

Question

A wooden boxcar is moving along a straight railroad track at speed v1. A sniper fires a bullet (initial speed v2) at it from a high-powered rifle. The bullet passes though both lengthwise walls of the car, its entrance and exit holes being exactly opposite each as viewed from within the car. From what direction, relative to the track, is the bullet fired? Assume that the bullet is not deflected upon entering the car, but that its speed decreases by 20%. Take v1=85km/hr and v2 = 650 m/s.

Answer 1

well, exactly opposite.That means the time the bullet went across the car, the train advanced the same distance as the angle of the bullet would have advanced.

Assume Theta is the angle the bullet entered.

Hmmmm. to figure the time the bullet took to cross the car, one needs to know the width of the car.
distance the car advanced:
distance=bulletspeed*time*sinTheta

Now the train: it advanced
distance=trainspeed*time
set them equal.
bulletspeed*sinTheta=transpeed*time

theta=arc sin (trainspeed/bulletspeed)
bullet speed is .8 of 650 Be certain to change km/hr to m/s

Answer 2

I'd love to know where this train came from...

Answer 3

To determine the direction from which the bullet is fired, we need to analyze the motion of the bullet relative to the boxcar.

First, let's convert the speed of the boxcar from km/hr to m/s:
v1 = 85 km/hr * (1000 m / 1 km) * (1 hr / 3600 s) = 23.61 m/s

Now, let's analyze the motion of the bullet relative to the boxcar.

When fired, the bullet has an initial speed v2 and it moves through the boxcar without being deflected. This means that the bullet's velocity is perpendicular to the walls of the boxcar.

Since the bullet passes through both lengthwise walls of the boxcar with entrance and exit holes directly opposite each other, we can conclude that the bullet's initial velocity is in the direction along the length of the boxcar.

Therefore, we can deduce that the bullet is fired from behind the boxcar, in the direction opposite to its motion along the straight railroad track.

In summary, the bullet is fired from behind the boxcar, relative to the direction of the track.