Physics question

[nothingflash]

Douglas Adams.

Which raises the question:

if a tree falls in a forest and it lands on a mime artist - does anybody care?

What if we threw a mime artist and a tree out of a plane......

[BMWST?]

But these objects are not being accelerated by gravity alone, so this does not apply in this case.

In this case the energy is being supplied by an engine. I've assumed the energy output of the engines remains constant in both cases (since that was what was said). If the energy output remains the same, then the two vehicles will not accelerate at the same rate.

The heavier car will take slightly longer to reach the same speed.He is asking abot top speed ,not accelleration

[Skyryder]

Big Dave said it best.


So here's another tricky one.


If a tennis ball was the only object in the universe. Can it move??


Skyryder

[p.dath]

Big Dave said it best.


So here's another tricky one.


If a tennis ball was the only object in the universe. Can it move??


Skyryder

Define movement, and the question will be answered.

[Emore]

If a tennis ball was the only object in the universe. Can it move??

No. Movement is only relative when measured against another object.

[Max Preload]

Jesus. It seems there are as many people on here who have no idea of the laws of physics as there are people who don't know how to indicate on roundabouts! I recall a thread a while back regarding CoG as well.

All other things being equal (friction & power) mass does not affect maximum achieveable velocity. It affects acceleration.

[Big Dave]

Jesus. It seems there are as many people on here who

lack social skills. :-P

[slofox]

If a tennis ball was the only object in the universe. Can it move??


Skyryder

Is the universe in itself an object?

[dipshit]

Is the universe in itself an object?

Not necessarily. We say things like 'the known universe'. That is the universe is everything we know of.

If there is no other matter or light or background radiation or gravity... absolutely nothing apart from one tennis ball... then there is nothing else as a reference point to measure its movement against.

[Flip]

Is the universe in itself an object?

Yes but there is still no fixed points of refrence so it's impossible to measure.

[scracha]

All other things being equal (friction & power) mass does not affect maximum achieveable velocity. It affects acceleration.

However, back in the real world, mass does affect friction.

[Marmoot]

The extra weight would create higher friction on the bearings (not the tyre contact patches with ground). But it is still an increased friction.
Friction = mass * friction coefficient.

Because of added friction, the force requirement to maintain equillibrium at higher speed is also higher. Therefore there is less force available to move the car. Ergo, the maximum speed decreases.
It can also be said as if the added friction acts as an additional set of brakes. What happens when you run your car while slightly pressing on the brake? It limits the maximum speed.

On the other hand, if you want to consider the fluid dynamic effects, the lighter car's maximum speed may or may not be limited by the amount of lift caused by the moving air underneath the car. Arguably, the weighted car may or may not benefit from this.
To properly analyse this to a conclusion, you would need a mathematical model on the airflow effect on both cars, and introduce the higher friction into the equation. Only then you would be able to judge whether the effect of added weight is more or less than the effect of lift that limits the lighter car. And only then would you be able to determine which one is faster.

And in regards to the tennis ball, if the universe is larger than the tennis ball then yes it can move relative to the center of the universe. But if the universe in the context is only as big as the tennis ball (e.g., if the universe size is determined by the object contained within) then no the tennis ball would not be able to move due to lack of space.

[MisterD]

So here's another tricky one.


If a tennis ball was the only object in the universe. Can it move??

I'm going to go with yes it can move, but no it can't be moved because there's nothing to apply any force to it...the sound of one hand clapping innit?

[Big Dave]

I'm going to go with yes it can move, but no it can't be moved because there's nothing to apply any force to it...the sound of one hand clapping innit?

Kicking Schrodinger's balls

[bogan]

if the tennis ball is the only thing in the universe, then is it really even a tennis ball, as there is nobeody there to define such a concept.

Also since the universe i generally considered infinite emptyness, no movement could ever be percieved or measured with respect to its confines, meaning any extra weight added to said tennis ball will not affect its top speed of null.