All vehicles accelerate at the same rate.

SVreX wrote: In reply to JohnRW1621: Depends on how high a cliff, and what angle you drop them at... ...but I am assuming you meant if both reached the gravitational rate of the acceleration of gravity of a free-falling object on Earth (9.8 m/s/s). If the cliff is not high enough for them to reach the acceleration rate of a free-falling object, the driven one will hit first. Barring that, if the dropped one is dropped at the exact same moment the driven one reaches the edge, the dropped one will reach the bottom first (because they will accelerate at the same speed, but the dropped one will begin it's vertical decent first, the driven one will be going horizontal for a period of time). If the dropped one is dropped nose first, it will reach the bottom first, because then we are not talking about the gravitational pull, we are talking about the air resistance, and the driven car (essentially horizontal) will have more air resistance than the dropped one (which has a drag coefficient of about Cd 0.34, depending of course on which model Ferrari we are talking about).

Not quite. If they are both released from over the edge of the cliff at the same time, they will hit the ground at (essentially) the same time. The acceleration due to gravity exists independently of the velocity of the one traveling horizontally (unless you are moving at near relativistic speeds, which we are not). The only factor that would make one fall slightly faster/slower is if, as you said, one is pointing nose down as opposed to flat to the ground.

Similarly, if you were to drop a bullet at the exact same time another one leaves the barrel of a gun, they would both hit the ground at the same time (presuming everything is flat and level).

The only other thing that would effect how long it takes one to fall is a combination of height, and curvature of the Earth. Something traveling at a high velocity (faster than any car) perpendicular to the ground will actually fall farther than something that falls straight down (e.g. free fall orbit). I figure that is not a large enough phenomenon to impact the results of this hypothetical experiment.

dean1484 wrote:

pinchvalve wrote: When dropped in a vacuum, all vehicles from a Ferrari to a Yugo will accelerate at the exact same rate. Fun fact for the day.

Ummmmm.. . .. Nope you forgot about gravity. Gravity gives things mass and mass is what is moved by HP and torques. Now remove gravity and the vehicles mass becomes equal. But if one has more force propelling one car than the other then even in zero gravity the car (or rocket) that produces the most thrust will be faster. Basic Hp / weight problem that we racers have been fighting for all eternity. Putting something in a vacuum only eliminates atmospheric resistance

To expand on what others have said. You are completely wrong except for your statement that a vacuum only eliminates atmospheric resistance. (Not sure if being silly or not though.)

Mass is an inherent property of matter and exists independent of the pull of gravity. Weight is a measurement of force. Usually we think of it as the force of gravity on the mass of an object. It can also be the measurement of force applied to move an object (e.g. ft/lbs.).

The inertia of an object (how hard it is to move) is a function of its mass, not its weight. An object with twice the mass will take twice as much force to accelerate at the same rate even in a vacuum.

When racing, it is not the weight of a car that has to be overcome to move it. It is the force required to move the mass. Weight only has an effect on how much force is on the contact patch of the vehicle, and therefore how much adhesion/rolling resistance they provide. So a more massive vehicle will have more rolling resistance. This is also how downforce works. Downforce effectively increases the weight of a vehicle (force towards the ground) without increasing the mass. The result is strong adhesion, but without any more inertia to resist lateral acceleration.

I'm gonna have to disagree on your bullet example.

Yes, they descend at the same rate. But they will only hit the ground at the same time if the overall height of the fall exceeds the other forces being applied, such as the inertia from the gun.

If I drop a bullet from 3" off the ground and fire one (level) 3" off the ground, the dropped one will hit the ground first. Every time.

In reply to SVreX:

The force of gravity accelerates them at the same rate. Only force that will change that is if there is a spin on the bullet that proviedes lift.

What innertia from the gun are you talking about that will affect the bullet? The inertia of the gun only resists it being moved backwards by the force of the charge.

In reply to SVreX:

The X/Y components are independent in the bullet example. Though IRL many rifle rounds tend to generate some lift for a couple hundred yards, apart from that, its spot on.

I'll just leave this here.

http://www.youtube.com/watch?v=A3QIXOKXSr0

Ya you are rite i interchanged the two. My bad. It is the mass that gravity then pulls on that creats weight. Does not cgange what i was getting at. Unless you get rid of gravity you still have weight. You can have a vaccum with gravity or without gravity. Wonder what the OP ment.

So, check me on this....

A 7mm may have a range of up to 5 miles or so, and moves at about 3000 fps. That's about 8 seconds of flight time.

If I drop it from a height of about .1 meter, it should hit the ground in about .14 seconds.

So, the 7 mm shot (level) at a height of .1 meters, will drop to the ground after .14 seconds, effectively reducing it's range from 26,000 feet to about 400 ft.

Right?

Regardless of evidence as shown by The Myth Busters here:

Toyman01 wrote: I'll just leave this here. http://www.youtube.com/watch?v=A3QIXOKXSr0

As the one who asked the question, I rule that we have a winner and it is:

itsarebuild wrote: African or European Ferrari?

Camelot, 'tis a silly place

In reply to SVreX:

Yep. The rate of drop should be the same assuming all other factors are the same.

Lots of variables though. I'm kind of amazed Mythbusters got as close as they did.

Beer Baron wrote:

SVreX wrote: In reply to JohnRW1621: Depends on how high a cliff, and what angle you drop them at... ...but I am assuming you meant if both reached the gravitational rate of the acceleration of gravity of a free-falling object on Earth (9.8 m/s/s). If the cliff is not high enough for them to reach the acceleration rate of a free-falling object, the driven one will hit first. Barring that, if the dropped one is dropped at the exact same moment the driven one reaches the edge, the dropped one will reach the bottom first (because they will accelerate at the same speed, but the dropped one will begin it's vertical decent first, the driven one will be going horizontal for a period of time). If the dropped one is dropped nose first, it will reach the bottom first, because then we are not talking about the gravitational pull, we are talking about the air resistance, and the driven car (essentially horizontal) will have more air resistance than the dropped one (which has a drag coefficient of about Cd 0.34, depending of course on which model Ferrari we are talking about).

Not quite. If they are both released from over the edge of the cliff at the same time, they will hit the ground at (essentially) the same time. The acceleration due to gravity exists independently of the velocity of the one traveling horizontally (unless you are moving at near relativistic speeds, which we are not). The only factor that would make one fall slightly faster/slower is if, as you said, one is pointing nose down as opposed to flat to the ground. Similarly, if you were to drop a bullet at the exact same time another one leaves the barrel of a gun, they would both hit the ground at the same time (presuming everything is flat and level). The only other thing that would effect how long it takes one to fall is a combination of height, and curvature of the Earth. Something traveling at a high velocity (faster than any car) perpendicular to the ground will actually fall farther than something that falls straight down (e.g. free fall orbit). I figure that is not a large enough phenomenon to impact the results of this hypothetical experiment.

Well, unless the Ferrari is driving fast enough as it goes off the cliff, as then it will start to orbit, and never hit the ground. I suspect Enzo always wanted to make a Ferrari that fast.

dean1484 wrote: Ya you are rite i interchanged the two. My bad. It is the mass that gravity then pulls on that creats weight. Does not cgange what i was getting at. Unless you get rid of gravity you still have weight. You can have a vaccum with gravity or without gravity. Wonder what the OP ment.

I think you (and a few others) are missing a key word in OP's hypothetical: "dropped." This isn't about a drag race, it's about purely gravitational acceleration in a vacuum, in which case, yes, a Veyron and an F100 would be (basically) equal.

when dropped in a vacuum (out space) the yugo will hit the ground sustaining minor cosmetic damage, the ferrari will burst into flames due to atmospheric friction.

SVreX wrote: So, check me on this.... A 7mm may have a range of up to 5 miles or so, and moves at about 3000 fps. That's about 8 seconds of flight time. If I drop it from a height of about .1 meter, it should hit the ground in about .14 seconds. So, the 7 mm shot (level) at a height of .1 meters, will drop to the ground after .14 seconds, effectively reducing it's range from 26,000 feet to about 400 ft. Right?

Because when you are firing it that far, you are arcing the shot to compensate for bullet drop. Firing long range requires compensating for wind and drop.

Functionally, you have added a vertical component to the velocity of the bullet that is working in opposition to gravity.

I didn't say anything about hitting a target, or compensating with an arc.

That would be cheating. An arced shot increases the amount if drop.

Straight shot. Hits the ground in 400 ft instead of 26,000. 1/62 of its potential range.

I'm with tuna55. Physics is pretty simple.

SVreX wrote: I didn't say anything about hitting a target, or compensating with an arc. That would be cheating. An arced shot increases the amount if drop. Straight shot. Hits the ground in 400 ft instead of 26,000. 1/62 of its potential range.

Dude, listen. Perfectly flat level ground to infinity. No air. Shoot a gun, drop a bullet, they hit the ground at the same time. The end. All stop.

It's high school physics, guys. Don't be like the Mythbusters forum

Wait a minute guys, we've been had, the OP was trying to start a physics argument on the internet, we let him succeed.

This thread is now about bacon.

Engineers are much more fun to poke than other species.

Settle down, guys. I made it through High School too.

What have we learned? 1- You don't solve problems by over-simplifying them, and 2- You don't explain problems by over-complicating the explanations.

I know the answers perfectly well, but this thread is quite a mess.

I'm still a big fan of the downforce-Ferrari-over-the-cliff approach.

Carry on. Back to the vacuum.

mndsm wrote: Did you know, a Yugo is faster than a ferrari? If the ferrari is doing 40, and the yugo is doing 55, the yugo will blow right by it.

No, God would not let that happen. I don't know what would happen, but the Yugo would NOT pass the Ferrari.

SVreX wrote: Engineers are much more fun to poke than other species.

Internet text does not convey tone/sarcasm well. And most of us are never really surprised when it turns out that people really don't understand how things work. The chance of someone misunderstanding basic Newtonian physics 101 is substantially higher than the chance of someone trolling to get a rise out of an engineer.

I've personally been privy to a ticket being thrown out of court after a physics teacher explained angular acceleration.

As for the Ferrari's downforce:

In a vacuum, there will be no air over the car's wing, so downforce will be nil.

In air, the car will immediately slow down after leaving the cliff, due to aerodynamic drag, so the amount of downforce will decrease quickly thereafter. Plus, the boundary layers between the car and the ground will have disappeared, and I don't know enough about fluid dynamics to estimate how that would affect the "pushing down" of the car.

Bacon.

In reply to Beer Baron:

Yeah, sorry about that. Didn't start that way, but man you guys got yourselves worked up fast.

Just figured I'd follow your lead.