physics question

Hairy · June 2007

if you were travelling in a car at 200mph and you leaned out the window and shot a gun the same way you were travelling would the bullett
a go faster than normal
b slower than normal

random discussion with me mate...

i guessed it to be b but i am thik as thuk

F

<center> I</center>R<center>M</center>

www.firmbikes.com

newmember · June 2007

how would it go slower than normal?

<center>
-
No "I Love Horses" Link Here.</center>

Crazy Dave C · June 2007

I'd say the same speed, it would just get to that speed quicker.

euan_333 · June 2007

Same speed, I reckon.

<hr noshade size="1">
Euan Crawford<h6>ª_ª</h6>

mbukjames · June 2007

I reckon it would go slower than normal because there will be more air hitting it and that will slow it down.

I don't deserve to have a sig..

hazzahulme · June 2007

Relative to you in the car, it'd go the same as normal. Relative to someone standing still at the side of the road, it'd go faster than normal.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

Hairy · June 2007

the gun body is being thrusted at 200mph as the car is travelling at that speed surly it would affect the speed of the bullet.

F

<center> I</center>R<center>M</center>

www.firmbikes.com

Crazy Dave C · June 2007

More air hitting it than when it's travelling at 600 mph, which is faster than the car is travelling?

nirveous · June 2007

I would go faster than normal, the bullet is already travelling at 200 mph, and then fired at however fast bullets go, thus making it faster.
Basically what hazzahhulme said in his first post.
Also, it sure as hell wouldn't go slower.
<hr noshade size="1">The Hardrock

miggillicuddy · June 2007

V=u+at

v-final speed
u-initial speed
a-accelleration
t-time

The accelleration on the bullet and the time are constant.
As the initial speed is greater; the final speed must be greater

...hence (a) It will reach a greater speed than normal.

No? Someone will no doubt inform me that that was a heap of bollocks but meh...

<hr noshade size="1"><center>~~StumpJumper~~</center>

hazzahulme · June 2007

It's not possible for it to go slower than the car, because then it would never leave the chamber, it'd just be pushed along at 200mph by the end of the chamber.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

roj279 · June 2007

same speed i reckon, its one for mythbusters!

<center> Rhythm </center>

Red Lemon · June 2007

It will travel faster than normal initially, but it will decelerate faster than normal too, due to the higher wind resistance. IIRC, wind resistance increases with the cube of velocity, but I could well be mistaken on that.

hazzahulme · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by miggillicuddy

V=u+at

v-final speed
u-initial speed
a-accelleration
t-time

The accelleration on the bullet and the time are constant.
As the initial speed is greater; the final speed must be greater

...hence (a) It will reach a greater speed than normal.

No? Someone will no doubt inform me that that was a heap of bollocks but meh...
<hr height="1" noshade id="quote"></blockquote id="quote">
That's just an equation of motion for an object, doesn't take it into account the car at all so that is pointless.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

Crazy Dave C · June 2007

If a particular bullet had a maximum airspeed of 600mph, then that is what it will travel, due to air resistance. If you are travelling in a car at 200mph then the bullet is already has an airspeed 200mph, and only needs to acellerate by another 400mph, meaning that it will reach that speed sooner. but not go any faster.

If you fired it into a wind of 50mph, then it would still attain an airpseed of 600mph, but hte groundspeed would be only 550mph. Assuming there is no other wind, then the bullet fired from the car would still travel at the same speed.

nirveous · June 2007

Well, in theory it would slow down, but this being a bullet, and they go very fast, and are very aerodynamic, I doubt it would slow down much faster than normal.

<hr noshade size="1">The Hardrock

hazzahulme · June 2007

How can a bullet have a maximum speed?

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

ToMBeMe · June 2007

http://mbuk.com/forum/topic.asp?TOPIC_ID=190297, read that about throwing a beer out a car.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by UH DH

How have you managed to avoid natural selection for so long?<hr height="1" noshade id="quote"></blockquote id="quote">

Crazy Dave C · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by hazzahulme

How can a bullet have a maximum speed?
<hr height="1" noshade id="quote"></blockquote id="quote">

Just like your car has a max speed, which is relative to it's propulsion, shape etc... And pretty much everything.

Shadow_Conspiracy · June 2007

I think he means as long as something powerful enough is firing it , it can always go faster.

it's kinda like a terminal velocity, the drag co-efficient probably has quite alot to do with it

<center>Bike!</center>

miggillicuddy · June 2007

Terminal velocity? Where air resistance equals the force of the object as it travels [?]

<hr noshade size="1"><center>~~StumpJumper~~</center>

Crazy Dave C · June 2007

That's the one. Terminal Velocity. I couldn't remember what it was called.

hazzahulme · June 2007

A bullet can go as fast as the size of the force pushing it, there is no maximum speed apart from the speed of light.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

miggillicuddy · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by hazzahulme

A bullet can go as fast as the size of the force pushing it, there is no maximum speed apart from the speed of light.
<hr height="1" noshade id="quote"></blockquote id="quote">
bollocks. It will always, eventually reach terminal velocity due to air resiststance. (I think)

<hr noshade size="1"><center>~~StumpJumper~~</center>

hazzahulme · June 2007

Terminal velocity only occurs when the only source of propulsion is gravity, hence falling straight down to earth.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

Red Lemon · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by hazzahulme

Terminal velocity only occurs when the only source of propulsion is gravity, hence falling straight down to earth.
<hr height="1" noshade id="quote"></blockquote id="quote">
Is that how terminal velocity is defined? So a car's maximum speed down a road isn't technically a terminal velocity?

miggillicuddy · June 2007

really? But still, it will always be slowed down by air resistance. As someone mentioned, the air resistance on a moving object is proportional to the object's speed. Therefore, as it's speed increases, the air resistance will increase also.

<hr noshade size="1"><center>~~StumpJumper~~</center>

hazzahulme · June 2007

As far as I am aware, terminal velocity refers to falling objects, and is the speed at which the force due to gravity is equal to the force due to air resistance. There is no external force therefore no acceleration as F=ma.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

neil h · June 2007

the simple answer to the question is that its all relative. from the reference point of the person in the car the bullet will be going slower than normal as they are moving at a closer speed to that of the bullet.

where as from someone outside observing the scenario from a static point the bullet will be moving at the normal speed the bullet would achieve.

hazzahulme · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by neil h

the simple answer to the question is that its all relative. from the reference point of the person in the car the bullet will be going slower than normal as they are moving at a closer speed to that of the bullet.

where as from someone outside observing the scenario from a static point the bullet will be moving at the normal speed the bullet would achieve.
<hr height="1" noshade id="quote"></blockquote id="quote">

No that's wrong. If the car is travelling at some speed V and the speed of the bullet coming out of a gun at rest is U. Then if the gun is fired out of the car in the same direction you are travelling then it's speed will appear to be U, if you are in the car. If you are watching from a stationary point, it will appear to travel at a speed of V+U.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Oldmacdonald

hazzahulme - Official second best font-of-all-knowledge 2007.
<hr height="1" noshade id="quote"></blockquote id="quote">

fleabag · June 2007

The bullet travels faster than usual!

This has been solved and proved so many times, I cant believe there has been any debate.

Light is one of the few, if not the only thing, that travels at the same speed regardless of the speed the source is traveling at.

<center>- - - - - - - - - - - - Y - o - U - - S - M - e - l - L - - f - U - n - N - Y - - - - - - - - </center>
<center>It's in yourdream , There's just one question...Should I kill? kill? Or should I be left behind? </center>

physics question

Comments

Categories