FORUMula1.com - F1 Forum

Discuss the sport you love with other motorsport fans

Dedicated to technical discussion...
User avatar
By bud
#93614
look cars do not produce thrust the only similar measurement is Torque measured in N/M
User avatar
By stonemonkey
#93636
The F1 car isn't expelling the mass its just pushing away from it.


so the car is pushing against the ground, the car exerts a force on the ground and by newtons laws, the ground must be exerting an equal but opposite force on the car, the car is accelerated in one direction, the ground is accelerated in the other (only by an extremely small amount) what is that if it isn't thrust? It doesn't matter that it's not an expanding gas escaping from a nozzle, you could sit in a shopping trolly throwing bricks and still call it thrust, the fact that the brick in this case is the size of a planet doesn't change anything.

look cars do not produce thrust the only similar measurement is Torque measured in N/M


The force that the tyre rubber exerts on the tarmac and vice3 versa is a frictional force (traction) and is measured in N.
User avatar
By stonemonkey
#93650
As well as that, there's a little experiment you could do.
Take an RC car (a fairly fast one would be better for this test) and a piece of paper, place the paper on a smooth floor like in the kitchen or something and put the car on the paper. Now push the control to make the car go, what happens?

EDIT:
Instead of the paper, you could use a flat topped trolly on wheels, the trolly moves one way, the car the other. If you repeat that but add weight to the trolly, the acceleration of the trolly will decrease, continue adding weight until the trolly has the mass of the earth.
By Gaz
#93728
As well as that, there's a little experiment you could do.
Take an RC car (a fairly fast one would be better for this test) and a piece of paper, place the paper on a smooth floor like in the kitchen or something and put the car on the paper. Now push the control to make the car go, what happens?

EDIT:
Instead of the paper, you could use a flat topped trolly on wheels, the trolly moves one way, the car the other. If you repeat that but add weight to the trolly, the acceleration of the trolly will decrease, continue adding weight until the trolly has the mass of the earth.


Yeh but the forward motion of the car would also decrease as the paper moves.

its still not expelling mass its just moving the paper.
By Gaz
#93731
The F1 car isn't expelling the mass its just pushing away from it.


so the car is pushing against the ground, the car exerts a force on the ground and by newtons laws, the ground must be exerting an equal but opposite force on the car, the car is accelerated in one direction, the ground is accelerated in the other (only by an extremely small amount) what is that if it isn't thrust? It doesn't matter that it's not an expanding gas escaping from a nozzle, you could sit in a shopping trolly throwing bricks and still call it thrust, the fact that the brick in this case is the size of a planet doesn't change anything.

It don't exert a force on the ground it pushes away from it, a jet engine is forced forward by expelling mass.

A shopping trolly thorwing bricks would be in a werid way thurst but a F1 cars motion comes from its wheels.


look cars do not produce thrust the only similar measurement is Torque measured in N/M


The force that the tyre rubber exerts on the tarmac and vice3 versa is a frictional force (traction) and is measured in N.



Think of it this way.

if you got your brick and sat in a shopping trolly in zero gravity and you threw the brick away from you, you would move in the opposite direction.

Same thing would happen if you strapped a rocket motor to yourself it would propell you in the opposite direction of the exhaust gasses.

Now if you got the F1 car and put that in to space the wheels would spin but it wouldn't move forward because its not able to push against anything or expell any mass.
User avatar
By stonemonkey
#93732
Yeh but the forward motion of the car would also decrease as the paper moves.


Now you're getting the idea, and the more massive the paper, the less it moves and the more the car moves.

its still not expelling mass its just moving the paper.


And does a propeller expell mass or does it just move air (or water)?
User avatar
By stonemonkey
#93733
Now if you got the F1 car and put that in to space the wheels would spin but it wouldn't move forward because its not able to push against anything or expell any mass.


Would a propeller do anything in space?
User avatar
By darwin dali
#93737
Now if you got the F1 car and put that in to space the wheels would spin but it wouldn't move forward because its not able to push against anything or expell any mass.


Would a propeller do anything in space?


Not likely.
User avatar
By bud
#93743
an internal combustion engine cannot produce thrust, whether it is used to turn a propeller or used to turn a wheel, both use friction to gain momentum.
As for the propeller in space no it cannot work as there is no air to push or pull a craft. While a rocket will work in space as it produces thrust :wink:
User avatar
By stonemonkey
#93746
Thrust is the force acting between two masses and accelerating them in opposite directions, does it matter if one of those masses comes from within the other?

A jet engine works on pretty much the same principle as a rocket except that most of the mass it's pushing against is atmospheric air sucked in through the compressor.
User avatar
By bud
#93748
yeah youre Rockets and Jets produce thrust. Internal combustion engines do not.
User avatar
By stonemonkey
#93750
what about an internal combustion engine powered tennis ball launcher in space bud?
By Gaz
#93800
Now if you got the F1 car and put that in to space the wheels would spin but it wouldn't move forward because its not able to push against anything or expell any mass.


Would a propeller do anything in space?


Neither would a jet engine.

still produces thrust though.

a Propller Expells air and thus produces thrust.

a Jet expelss superheated compressed air and thus produces thurst

a rocket motor expells various compressed ignited gasses to produce thrust

an F1 car does not expell any propellent only exahust gasses that do not produce thrust sufficant to move it.

the car's wheels turning is tractive effort, not thrust.
User avatar
By stonemonkey
#93817
Neither would a jet engine.

still produces thrust though.


It would if it carried it's own air supply (the same as would go for an internal combustion engine in space) but then it would just be a rocket.

a Propller Expells air and thus produces thrust.

a Jet expelss superheated compressed air and thus produces thurst


I agree.

a rocket motor expells various compressed ignited gasses to produce thrust


Not always, the propellent does not necessarily need to be the fuel. Ion rockets accelerate charged particles using electromagnetic fields to produce thrust. And Scaled Composites spaceship one just released air through valves to manouver in space.

an F1 car does not expell any propellent only exahust gasses that do not produce thrust sufficant to move it.


I disagree, the ground the car is sitting on is the propellent.

I do agree that an internal combustion engine creates torque but the engine is only one part of the system which includes the car and whatever it is sitting on, sit a car on a trolly and accelerate. The car accelerates in one direction and the trolly accelerates in the other, the means by which that force is applied is irrelavent, it could be electromagnetic, it could be tractive (rolling wheels or walking on legs), it could be explosive etc. The trolly the car is sitting on is the propellent, in the case of a car on the ground it would be planet Earth that is the propellent..

Take a catherinewheel firework for example, it is powered by rockets but it goes round. Torque from rockets?
  • 1
  • 2
  • 3
  • 4
  • 5
  • 8

See our F1 related articles too!