Question about a fly?

PaulStat · 9 Mar 2006 at 16:53

Ok so a fly is in flight in a car that is travelling at 80mph, since the fly isn't actually touching the car as such. Does it have to fly 80mph in the same direction to avoid being splatted against the back window?

Clarkey · 9 Mar 2006 at 16:54

the back window? It owuld be splattered on the front window before it made it to the back, no way a fly can go 80mph lol.

spirit · 9 Mar 2006 at 16:55

man loads of people with these q's today, thinking thursday!

Raikiri · 9 Mar 2006 at 16:55

Clarkey said:
the back window? It owuld be splattered on the front window before it made it to the back, no way a fly can go 80mph lol.

The fly is already in the car before it starts travelling...

My answer is a question, do you run at 80mph when in a car?

Gilly · 9 Mar 2006 at 16:55

PaulStat said:
Ok so a fly is in flight in a car that is travelling at 80mph, since the fly isn't actually touching the car as such. Does it have to fly 80mph in the same direction to avoid being splatted against the back window?

:/

Does the air inside the car move at 80mph to avoid being left behind?

No it does not.

Do you have to move at 80mph to keep up with the car?

No you do not.

Whats with all the inane questions these days? :confused:

PaulStat · 9 Mar 2006 at 16:56

Clarkey said:
the back window? It owuld be splattered on the front window before it made it to the back, no way a fly can go 80mph lol.

which ever window it is, but you see my point?

Sic · 9 Mar 2006 at 16:56

i started reading this and thought "what's with all the questions about speed and whatnot?!" but it's actually a fun question. and why would it fly into the front? if a car was moving forward at 80mph and a fly was hovering then it'd get hit by the back window, surely?

Gilly said:
Do you have to move at 80mph to keep up with the car?

no, but because you're sat on the seat, you're being pulled along by the car, so the car is making you move 80mph. if you were floating in the car and it started moving, i'm fairly sure you'd go through the back window. unfortunately, i cant recreate this to prove it.

ChroniC · 9 Mar 2006 at 16:57

if it started in the car then no, its called enersure (i dont know how to spell it though, thats called being thick

)

Sic · 9 Mar 2006 at 16:58

ChroniC said:
if it started in the car then no, its called enersure (i dont know how to spell it though, thats called being thick )

inertia?

Dreadi · 9 Mar 2006 at 16:59

thats like saying when your in a plane thats at exactly the speed of sound in flight, if you get up and walk from one end to the other, have you personally just gone fast then the speed of sound

ChroniC · 9 Mar 2006 at 16:59

Sic said:
inertia?

thats the one, thanks

see hes smart

Blinkz · 9 Mar 2006 at 17:00

you've just got to remember that all speed is relative. In a car, all of its contents are moving at 0mph relative to the car, but the car is moving 80mph relative to the road. So the fly will be flying at its normal speed, but relative to the road it will be its relative speed to the car + cars speed to the road.

SaBBz · 9 Mar 2006 at 17:01

It's all to do with the frame of reference

Rich_L · 9 Mar 2006 at 17:02

Hmmm.

I reckon while the car was accelerating the fly would have to match the cars acceleration to stay in one place, but once the car was travelling at a steady pace it could fly around as normal. Alternatively it could land and let the car body accelerate it instead!

Think about if you are throwing a tennis ball in the air in a car - if the car accelerates while the ball is in the air the ball moves to the back of the car. Likewise if the car brakes suddenly when the ball is in the air it moves to the front.

Could be totally wrong though

Enfield · 9 Mar 2006 at 17:03

what a dumbass question lol

PaulStat · 9 Mar 2006 at 17:03

I knew there was a reason why this couldn't be the case, but couldn't for the life of me think why, anyway thankyou for clearing that up

Gilly · 9 Mar 2006 at 17:05

Sic said:
no, but because you're sat on the seat, you're being pulled along by the car, so the car is making you move 80mph. if you were floating in the car and it started moving, i'm fairly sure you'd go through the back window. unfortunately, i cant recreate this to prove it.

When an astronaut is floating in his shuttle in space is he having to hold on to stop himself being propelled through the back wall?

Scuzi · 9 Mar 2006 at 17:05

If the car set off from a standstill and the fly was hovering in the car, it would get splatted on the back windscreen. Even though the fly is 'inside' the car, it is not connected to it therefore is hovering in a constant position in space. The speed of the air has nothing to do with it as I flys wings do not rely on airspeed to fly.

So the fly is hovering inside the car, what if you removed the roof? The fly is outside the car. Forget about airspeeds and whatnot as it is technically irrelevant.

Read up on the conservation of momentum and inertia principles.

Ricochet J · 9 Mar 2006 at 17:05

Well yeh it's inertia. If you had all the windows open then perhaps the fly would have to keep up with the car's speed.
If you think that its already travelling at 80mph default, then any speed ontop of that would be the ms-². Which we all know is accelaration

(Change in velocity over the time taken for change)

Visage · 9 Mar 2006 at 17:07

Rich_L said:
Hmmm.

I reckon while the car was accelerating the fly would have to match the cars acceleration to stay in one place, but once the car was travelling at a steady pace it could fly around as normal. Alternatively it could land and let the car body accelerate it instead!

Think about if you are throwing a tennis ball in the air in a car - if the car accelerates while the ball is in the air the ball moves to the back of the car. Likewise if the car brakes suddenly when the ball is in the air it moves to the front.

Could be totally wrong though

Nope - you're right.

In fact, its a derivation of this (but with light beams) that gives one of the simplest derivations of time dilation in special relativity.