If a rifle is fired horizontally & a bullet is dropped from the same height and same time, will they hit the?

Question

ground at the same time?

Answer 1

Yes! Gravity works equally on each bullet!

Answer 2

No they will not... but hold on, before you give me a thumbs down, it has nothing to do with the fact that the fired bullet is traveling along an arch or anything.

When you fire a bullet it travels forward as muzzle velocity and down at gravity velocity. If the earth were perfectly flat and discounting any obstacles or updrafts causing the bullet to remain aloft longer, the two bullets will hit at exactly the same time. Unfortunately as Christopher Columbus intended to prove (but failed), the Earth isn't flat.

Since the bullet is fired in a arch, and the Earth curves as the bullet travels, gravity must overcome the slightly increased inertia of the bullet (as far as the gravity is concerned) trying to cause the bullet to curv away from the Earth. (If in the gravity model, you flatten the Earth, you arch the bullet path by the same amount and you can see the effect that gravity need to overcome to pull the bullet down.)

The effect is that the fired bullet will ideally land just after the bullet you dropped does [probably by an unmeasurably small amount]. Just how long is proportional to the caliber of the bullet, wind resistance, obstacles, spin of the bullet, etc.

To get both to land at the same time, fire/drop both in a vacuum over a planer gravity source.

(Yes, I am aware that the amount of curvature of the Earth that the fire bullet traverses should be minute. I'm also aware of the word exact.)

Gravity work on all objects equally. This is regardless of the fact that one happens to be moving in one particular direction parallel to the plane of gravity at several hundred feet per second.

Now, if you really want to get into physics, we can talk about Einstein's theory of special relativity. Talk about time-dilation and you can (if I understand this correctly) have the fired bullet hit the ground _before_ the one you dropped does.

Answer 3

I don't know physics, but I would guess that a bullet shot horizontally would travel for a second or two before dropping. If you knew the distance that the horizontal bullet would travel, and dropped the other bullet from the same height, you might find that they drop in the same moment. But if you stood on a long flat space, say a runway, and shot a bullet horizontally from your shoulder height, and at the same moment dropped a bullet from shoulder height, the one you dropped would hit the ground far faster than the shot bullet.

Answer 4

In a controlled environment, yes, but with the spin of the bullet and the wind resistance, it is not a sure thing in the real world.

Don't know why I'm getting thumbs down here, its not that I don't know that gravity works equally on both, the question said "fired horizontally", and this, in the real world is subject to all of the extraneous forces exerted on the bullet. The path is an arc in general, but it is virtually impossible to predict the exact path of the bullet. With the spin and wind resistance, think Bernoulli principle here, the path of the bullet will deviate from a perfectly curved path. That's all I'm saying.

Answer 5

In a perfect world if fired on a perfectly flat surface they would hit at the same time however in reality different slugs from different rifles react differently due to the rate of speed and spin of the bullet. Some rifles will cause a slug to rise or take weird curves.

Answer 6

They will hit at the same time as long as the bore of the rifle is exactly horizontal and you have a very large, flat area.

Gravity pulls down the same on all objects regardless of their forward momentum.

Answer 7

Definitely Yes!!
Gravity acts equally on all things. In a vacuum a feather & a coin will hit the ground at the same time. Its friction that slows the feather down

Answer 8

It depends on what altitude they are dropped and shot.

Remember, a bullet traveling at muzzle velocity has a long way to go, then one dropped.

I would venture to say that the one dropped will hit faster than the one fired, because the one fired has to have friction slow it down, and its in an arc so its not governed by gravity until it has "spent" its forward momentum.

Yep, the one dropped will hit faster than the one fired horizontally... (provided that the one "shot" will not hit any obstructions).

I wish you well..

Jesse

Answer 9

They will hit the ground at the same time, ignoring air resistance, because the acceleration acting on both is 9.81m/s. If acceleration is taken into account then their surface areas will have to be taken into account. The one with the greater air resistance will take more time.

Answer 10

True. But only if there is no wind and the fired bullet doesn't hit anything.