# A bullet droppet and a bullet fired

• TSN79
In summary, it is possible for a bullet dropped from a height of 1 meter and a bullet fired horizontally from the same height to hit the ground at the same time, assuming there is no air resistance and the Earth's curvature is negligible. However, for a more detailed discussion of exterior ballistics, this may not hold true.
TSN79
I was told something I really found hard to believe. Two cases:

A) You drop a guns bullet from a height of let's say 1 meter.

B) You fire the bullet from the gun horizontaly, also 1 meter above ground.

What I'm told is that these two bullets will hit the ground at the same time if dropped/fired simultaneously since gravity starts "working" on them at the same time. It sounds amazing, can it really be??

Short answer for purposes of learning basic physics, "Yes." Long answer for purposes of detailed discussion of exterior ballistics, "No." "Yes" assumes an infinite flat plane over which the bullet is fired, and that the bullet travels in vacuum (no lift due to the gravitational density gradient when fired through air or some other gaseous medium).

Assuming, as Bystander said, "vacuum" and so no air resistance ("infinite flat plane" is not as important; the Earth is large enough that its curvature within the range of a typical bullet is negligible) then the only force acting on a bullet is gravity. Downward acceleration is the same in both cases. Since horizontal and vertical motions are independent the fired bullet, which has only horizontal initial velocity, and the dropped bullet have the same initial vertical velocity, 0, and so exactly the same vertical motion.

Thx, guys :) Still, pretty amazing.

Earth's curvature? ~4" a mile. Time? 1/4 s to .7s for 2 to 8' drops. Muzzle velocity? 2000-4000 f/s. 1-2" extra drop time? 1-2 or 3% --- actually, for a classic, this is one of the lousier exercises.

## 1. What is the difference between a bullet dropped and a bullet fired?

A bullet dropped is released from a stationary position and falls due to the force of gravity. A bullet fired is propelled by the force of gunpowder and travels through the air with much greater velocity.

## 2. Do bullets dropped and fired follow the same trajectory?

No, they do not. Since a bullet dropped has a lower initial velocity compared to a bullet fired, it will follow a shorter and more curved path due to the effects of gravity. A bullet fired will travel further and follow a flatter trajectory.

## 3. How does air resistance affect a bullet dropped and a bullet fired?

Air resistance affects both bullets, but to a greater extent for the bullet fired. As the fired bullet travels through the air, it experiences drag, which slows it down and causes it to follow a curved trajectory. A bullet dropped, being released from a stationary position, experiences less air resistance and falls straight down due to gravity.

## 4. Which bullet will hit the ground first, a bullet dropped or a bullet fired?

Neglecting air resistance, both bullets will hit the ground at the same time. However, in real-world scenarios, the bullet fired will hit the ground first due to the effects of air resistance.

## 5. Can a bullet fired ever drop below a bullet dropped?

No, a bullet fired will always have a greater velocity than a bullet dropped. Therefore, it will always travel further and never drop below a bullet dropped.

• Introductory Physics Homework Help
Replies
6
Views
2K
• Classical Physics
Replies
28
Views
2K
• Introductory Physics Homework Help
Replies
11
Views
1K
• Introductory Physics Homework Help
Replies
10
Views
2K
• Introductory Physics Homework Help
Replies
13
Views
1K
• Introductory Physics Homework Help
Replies
7
Views
2K
• Introductory Physics Homework Help
Replies
14
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
5K
• Introductory Physics Homework Help
Replies
9
Views
3K