Stupid friday question

[The AD]

Originally posted by Viva
If there's a truck, there's gravity. If there's a road...

So change it to "a guy is strapped down to the back platform of a caboose on a mag-lev train, wearing a spacesuit because it's a vacuum with no gravity." Will that satisfy the no gravity thing you seem to be stuck on?

[bigtwig00]

vacum is the key word here the ball would stop

[The AD]

Originally posted by bigtwig00
vacum is the key word here the ball would stop

No, I think cmor's right, the action of throwing the ball would impart a (equal and opposite) force to the truck that would cause the truck to accelerate to more than 60 mph. The truck is much more massive than the ball, so it wouldn't be much, but it wouldn't be zero either.

[Pinner]

If you were travelling in a car at the speed of light and turned on the headlights, would you see them?

[Beaver]

Originally posted by Pinner
If you were travelling in a car at the speed of light and turned on the headlights, would you see them?

Nope. when you turned on the headlights, light would pour into the headlights from all around until the battery was full. Then the battery would explode. Very dangerous. Next time you are traveling at light speed keep the lights off for safety.

[cmor]

[re-entering geek mode]you couldn't turn on the headlights, time would be stopped. [/exiting again]

Talking about stuff at the speed of light isnt super useful, talking about stuff real close to the speed of light is. If you were real close to the speed of light your headlights would look the same as if you were stationary. Oh shit. I thought had exited geek mode. sigh.

[Kellie]

first of all, there is gravity, even in a vacuum. the only way that gravity disappears is if you do this in outer space where there are no trucks, roads, or maggots (and no places we know of to ski, so why even consider this world).

let's assume that you are not the incredible hulk and that your throw has no impact on the truck's velocity. let's further assume that our frame of reference is a hitchiker standing on said road watching the truck go by without picking him up.

the vacuum means that there is no air resistance to the truck or the ball, so that when the ball is thrown, both the ball and truck are travelling at 60mph. from the reference point of the hitchiker, however, only the car moves at 60mph and the ball will fall directly to the ground from the point it was thrown.

the moral here is that the hitchiker gets screwed cuz the truck driver gets to go skiing and all he gets is a stupid baseball that has no relevance to skiing pow . . .

[bigtwig00]

Originally posted by The AD
No, I think cmor's right, the action of throwing the ball would impart a (equal and opposite) force to the truck that would cause the truck to accelerate to more than 60 mph. The truck is much more massive than the ball, so it wouldn't be much, but it wouldn't be zero either.

cant say it any better then that. the same force that would be put on the ball would also be put on the truck going the oppisite direction (what ad is saying). as far as the ball goes it wouldnt travel at all but jsut drop to the ground. i asked my bio teach today ps. im 15

[Viva]

Originally posted by The AD
So change it to "a guy is strapped down...

Hey there fella, now you're talkin' my language...

[Viva]

Originally posted by bigtwig00
cant say it any better then that. the same force that would be put on the ball would also be put on the truck going the oppisite direction (what ad is saying). as far as the ball goes it wouldnt travel at all but jsut drop to the ground. i asked my bio teach today ps. im 14

No, not really because the action of throwing a ball (or any object) imparts forces in different directions.

[bigtwig00]

Originally posted by Viva
No, not really because the action of throwing a ball (or any object) imparts forces in different directions.

they said eariler that the ball was being throughen in the oppisite direction or parallel to the trucks movement and unless your sidearmed or somthing the oppisite reaction to the original force would be drectly back in the same direction of the trucks movement

[AntiSoCalSkier]

OK, the fact that throwing the ball will impart a force on the truck is completely irrelevant to the original problem statement. The original problem states that the truck is moving at 60 mph, and the ball is thrown at 60 mph relative to the truck. This statement allows you to ignore what led up to the event of the ball leaving the hand of the thrower. If you want to know what happened, the driver of the truck too into account the slight change in momentum, and adjusted the accelerator at that instant so that there was no change in the truck's speed.

Oh, and I've got a BS in phsyics, so what I say is True, and there can be no argument.

[Snow Dog]

Originally posted by AntiSoCalSkier
Oh, and I've got a BS in phsyics, so what I say is True, and there can be no argument.

My BS is bigger than your BS.

[bigtwig00]

what is your point we already answered that the ball would stop dead, the whole part of the truck is jsut extra

[phUnk]

Originally posted by bigtwig00
cant say it any better then that. the same force that would be put on the ball would also be put on the truck going the oppisite direction (what ad is saying). as far as the ball goes it wouldnt travel at all but jsut drop to the ground. i asked my bio teach today ps. im 15

Wow. You're 15 (or 14) and illiterate.

teh world is youre oyster!

[bigtwig00]

Looks like I'm a step ahead of you.

[powstash]

Originally posted by hev
it would fall straight to the ground the truck was passing over. From the perspective of you in the truck it would apear to be traveling backwards at 60.

I second this.

[bigtwig00]

Originally posted by cmor
[re-entering geek mode]you couldn't turn on the headlights, time would be stopped. [/exiting again]

Talking about stuff at the speed of light isnt super useful, talking about stuff real close to the speed of light is. If you were real close to the speed of light your headlights would look the same as if you were stationary. Oh shit. I thought had exited geek mode. sigh.

yeah kinda, your headlights would apear to extend from your car at the same speed under the speed of light. ex. speed of light-5 = beam of light appearing to be traveling 5 mph extending from your car.

[Mountainman]

Originally posted by powstash
I second this.

But how does it fall when there is no gravity?

[Viva]

Originally posted by Pinner
If you were travelling in a car at the speed of light and turned on the headlights, would you see them?

Actually, you'd see something like this, minus the Wooky:

http://www.theforce.net/theater/soft...es/fig1-2a.jpg

Edit: I take that back; that's no Wooky.

[Mountainman]

maybe you would see this...

[Blurred Elevens]

Originally posted by Telephil
What would happen to the ball, would it stop?

Forget the ball, Look at that bus! Holy shit, is that Tannor sitting across from Brady??!

[Spats]

Originally posted by The AD
You're right. Nice catch you loser!

I'm still not sure how that truck stays on the road with no gravity, though.

It was wearing heavy boots.

[The AD]

Originally posted by Kellie
first of all, there is gravity, even in a vacuum. the only way that gravity disappears is if you do this in outer space where there are no trucks, roads, or maggots

Yeah right, as opposed to the scads of places around where you can drive a truck in a vacuum.

So let's simplify: if there's gravity the ball falls to the ground at 9.8 m/s^2, if there's no gravity the ball doesn't move, other than the rotation that the thrower gave to it.

[Snow Dog]

Originally posted by The AD
So let's simplify: if there's gravity the ball falls to the ground at 9.8 m/s^2, if there's no gravity the ball doesn't move, other than the rotation that the thrower gave to it.

While you're nitpicking, 9.8 m/s/s is the acceleration due to gravity on Earth at the Equator. Elsewhere in the universe it will have different values.