The Naked Scientists Forum

helpneeded

• First timers
• Posts: 2
Physics - about size and speed
« on: 28/07/2005 12:27:22 »
Hey guys,
just a question...
do larger objects slide down a slide faster, slower or at the same rate as smaller objects?
does anyone know where i could get more information for this from?
thanx

Ultima

• Sr. Member
• Posts: 488
Re: Physics - about size and speed
« Reply #1 on: 28/07/2005 14:00:49 »
Depends on the object; friction and air resistance will depend on the shape and texture. If the objects are of the same mass, gravity acts on them the same way. If you are talking about rolling and not sliding with a non uniform mass there are crazy momentum things to think about... although I didn't get that far in mechanics . If the slide was also curved and flicked at the end (a parabola), and the masses weren't uniform this will have a big effect. For more information pick up a Maths textbook with "Advanced Mechanics" written on the top . Or Google it!

wOw the world spins?
« Last Edit: 28/07/2005 14:03:14 by Ultima »

gsmollin

• Hero Member
• Posts: 749
Re: Physics - about size and speed
« Reply #2 on: 28/07/2005 18:38:02 »
quote:
Originally posted by helpneeded

Hey guys,
just a question...
do larger objects slide down a slide faster, slower or at the same rate as smaller objects?
does anyone know where i could get more information for this from?
thanx

The force of friction between any pair of dry, unlubricated surfaces follows two empirical laws. (1) It is approximately independent of the area of contact, over wide limits, and (2) it is proportional to the normal force.

So larger and smaller is irrelevant, unless larger means heavier. In any event, lighter objects slide faster than heavier objects, when the surfaces in contact are made of the same materials, with the same coefficient of friction.

You can go to your library and get any freshman physics book, and it will be in there. Look up Particle Dynamics, Frictional Forces.

David Sparkman

• Sr. Member
• Posts: 234
Re: Physics - about size and speed
« Reply #3 on: 28/07/2005 21:23:16 »
When dealing with heavier objects, you can get deformation of the surface(s) and that can increase friction. Besides imagining a heavy steel ball rolling down the slide and deforming the metal of the slide, consider the simpler fact that higher tire pressure leads to less deformation of the tire, and therefore better gas milage... I know, I write long sentences.

David

helpneeded

• First timers
• Posts: 2
Re: Physics - about size and speed
« Reply #4 on: 29/07/2005 13:31:56 »
Wow that was great information, thanks for all your help

The Naked Scientists Forum

Re: Physics - about size and speed
« Reply #4 on: 29/07/2005 13:31:56 »