Does weight affect downhill speed?
#126
Prefers Cicero

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#127
Temporary Earthling
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Yes, air resistance, not ****ing weight! P. S. Thanks for the laugh.
#128
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#130
A table tennis ball is 40mm in diameter, and weigh 2.7 grams.
A lead sphere of 40mm in diameter weighs ~380 grams.
Same size, same shape, same Cd, but different weight.
You are saying they will have the same terminal velocity.
A lead sphere of 40mm in diameter weighs ~380 grams.
Same size, same shape, same Cd, but different weight.
You are saying they will have the same terminal velocity.
#131
The tennis ball is fuzzier.

You can stack coffee filters to compare the terminal velocities of objects of different masses having roughly the same Cd. A stack will have a higher terminal velocity than a single one. Still, I think what supramax is saying is that the difference is due to air resistance, - which is true. That's not the same as saying the lighter object has more air resistance and that's why the terminal velocity is lower.
Last edited by tjspiel; 06-29-09 at 11:36 AM.
#132
I took AP physics in HS. So I was a nerd and so was everybody else in the class. But even the nerdiest among us would have had a good laugh at this thread. Thanks everybody.
BTW supramax is just drunk don't bother arguing.
BTW supramax is just drunk don't bother arguing.
#133
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I can't remember who it was (and I'm not gonna check) that didn't want to hear this again, but The speed of a falling body is independent of its weight.
#134
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#135
#138
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Keeping the other factors constant, including a present normal atmosphere....
make it heavier, it will fall faster.
make it larger, it will fall slower
increase the Cd, it will fall slower
shave its legs, others will laugh at it if it happens to be a guy.
#139
Weight, all buy itself will not determine terminal velocity. The combination of weight, size and Cd will determine a terminal velocity.
Keeping the other factors constant, including a present normal atmosphere....
make it heavier, it will fall faster.
make it larger, it will fall slower
increase the Cd, it will fall slower
shave its legs, others will laugh at it if it happens to be a guy.
Keeping the other factors constant, including a present normal atmosphere....
make it heavier, it will fall faster.
make it larger, it will fall slower
increase the Cd, it will fall slower
shave its legs, others will laugh at it if it happens to be a guy.
#140
Gravity pulls on objects with the same acceleration, so when you remove other forces acting on an object (the resistance of air, i.e. in a vacuum) then obejcts will fall at the same speed. That doesn't mean the acceleration is constant, that just means the force being applied is:
F = MA = M * 9.8(m/s)
The greater the mass, the more force being applied. This doesn't matter though, because it takes more force to accelerate a greater mass so they accelerate at a constant rate. If those same objects encounter an opposing force, though (i.e. wind resistance), that is dependant on surface area, not mass, then of 2 objects with the same surface area the one with more force (mass) will accelerate faster since it's ratio of force to mass is higher.
I dunno, you could always keep closing your eyes and screaming - that may make what you're saying more true.
I've responded to yet another one of these though... what's wrong with me?
#141
If that were the case, you could modify the weight of an existing object and the speed of the object wouldn't change. If i drop a beach fall from building and time it, then drop the exact same beach ball from the same building but this time filled with water and not air it will reach the ground sooner.
Instead of air, fill the beach ball with helium.
I'm sure it will fall just as fast as the one filled with sand.
#142
Dances With Cars
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pssst the world ... she is flat like a pancake. We never landed on the moon either.. that video was shot in Chile
#143
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Weight, all buy itself will not determine terminal velocity. The combination of weight, size and Cd will determine a terminal velocity.
Keeping the other factors constant, including a present normal atmosphere....
make it heavier, it will fall faster.
make it larger, it will fall slower
increase the Cd, it will fall slower
shave its legs, others will laugh at it if it happens to be a guy.
Keeping the other factors constant, including a present normal atmosphere....
make it heavier, it will fall faster.
make it larger, it will fall slower
increase the Cd, it will fall slower
shave its legs, others will laugh at it if it happens to be a guy.

Anyways, I don't see any point in continuing to debate this with the "objects with different weights fall at different rates" crowd. That was disproven long ago.
Last edited by supramax; 06-29-09 at 04:41 PM.
#144
The force of gravity is constant. Here's an old and often used experiment for you to try, that proves that heavier objects do NOT fall faster. You gotta hammer? Hold it parallel to the ground and drop it. Do report your findings. 
Anyways, I don't see any point in continuing to debate this with the "objects with different weights fall at different rates" crowd. That was disproven long ago.

Anyways, I don't see any point in continuing to debate this with the "objects with different weights fall at different rates" crowd. That was disproven long ago.
#145
I think that supramax somehow imagines that some of the rest of us disagree with the general principle that when air resistance is negligible objects fall at the same speed regardless of weight. Then again, he might just be trolling.
It's surprisingly hard to disengage a troll once you taken up the argument, isn't it?
"Do not answer fools according to their folly, or you will be a fool yourself." -Proverbs 26:4
"Answer fools according to their folly, or they will be wise in their own eyes." -Proverbs 26:5
#147
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I'm just a fat old lady troll.
I can't remember what else I've been called since the unibrows of the old boys club got frustrated with their jointless thumbs, but that's enough. Like I said, I'm not going to debate this any further. I've been completely unambiguous in what I've stated and I'm still being asked moronic questions or being attacked by gormless idiots. I think the real problem here is that some of you are sorrowfully lacking in reading comprehension skills.
It's bed time again. Bon soir.
I can't remember what else I've been called since the unibrows of the old boys club got frustrated with their jointless thumbs, but that's enough. Like I said, I'm not going to debate this any further. I've been completely unambiguous in what I've stated and I'm still being asked moronic questions or being attacked by gormless idiots. I think the real problem here is that some of you are sorrowfully lacking in reading comprehension skills.It's bed time again. Bon soir.
#148
I'm just a fat old lady troll.
I can't remember what else I've been called since the unibrows of the old boys club got frustrated with their jointless thumbs, but that's enough. Like I said, I'm not going to debate this any further. I've been completely unambiguous in what I've stated and I'm still being asked moronic questions or being attacked by gormless idiots. I think the real problem here is that some of you are sorrowfully lacking in reading comprehension skills.
It's bed time again. Bon soir.
I can't remember what else I've been called since the unibrows of the old boys club got frustrated with their jointless thumbs, but that's enough. Like I said, I'm not going to debate this any further. I've been completely unambiguous in what I've stated and I'm still being asked moronic questions or being attacked by gormless idiots. I think the real problem here is that some of you are sorrowfully lacking in reading comprehension skills.It's bed time again. Bon soir.
So you are saying the table tennis ball (aka ping-pong ball) will fall at the same speed as a 40mm lead sphere?
#149
Surf Bum
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I don't remember him saying anything of the sort. Read what he really said. ("The speed of a falling body is independent of its weight.") Think about it. Maybe you'll figure out why he keeps saying it!
I suspect what he is getting at will be clearer to you if you reverse what he is saying and see if you think that is correct: i.e. if you don't believe the speed of a falling body is independent of its weight, do you feel it is dependent on its weight?"
I suspect what he is getting at will be clearer to you if you reverse what he is saying and see if you think that is correct: i.e. if you don't believe the speed of a falling body is independent of its weight, do you feel it is dependent on its weight?"
#150
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I think he is just being excessively pedantic at everyone's expense. Move along, nothing to see here...







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