Barrels on a hillside conundrum
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I don't remember my high school physics all that much, but isn't it the heavier one that reaches its terminal velocity first (or is it that the heavier one has a higher terminal velocity)? So, probably the concrete-filled barrel.
Acceleration due to gravity is constant regardless of weight. The only different factor would be impact of wind resistance, which effects terminal velocity.
In this case, it depends on neither, assuming the barrels are the same except for contents. Gravity should accelerate both at the same rate.
He did say both were "filled". But you're right, any air would affect the way it bounces down the hill, impacting speed. This would be cleaner if they were dropped from a tower or plane.
I agree that if they crush the box with the bird, that would be ideal.
Cycleguy007
Banned
I thought this only happened in a vacuum?
If they are truly equal (in weight, size, etc) then if they are released at exactly (to the ms.) they will reach the bottom at the same time.
But don't forget one is liquid-filled and the other is solid and they are rolling, not dropped.
I saw this demonstrated on one of those tv science-shows-on-a-budget (not Mythbusters) but can't remember off-hand what the answer was, but believe the two did not roll at the same rate.
I could see the fluid being a factor if the barrel was only partially filled. Then you'd get an amplified impact on the rolling action. I could also see a longer inertial delay in the fluid as the barrel starts to roll. Kind of like the anti sway tanks on the top of really tall buildings (but those tanks are only half full).
Yeah I agree with you on that, but I'm thinking there is also an effect because the water doesn't all start rotating in sync with the barrel so now there's some "friction" or some other force added into the mix.
Tried surfing the web to find the info, but no luck so far. Wish I could remember what show I saw it on....
Edit: Ah-ha! Found something similar..... A plastic bottle filled with water will roll down a ramp faster than a plastic bottle filled with ice due to the difference in angular inertia.... all the ice has to start rolling at the same time as the bottle, while the water does not - making it easier for it to start rolling.
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Galileo Galilei is said to have dropped two cannon balls of different masses from the tower of Pisa to demonstrate that their speed of descent was independent of their mass
Actually, what he did was roll different size steelballs down a slope which is what the OP intends but because one is filled with liquid the dynamics of fluid may have something to do with the result
Galileo discovered they reach the bottom at the same time so the question is a very good one as it defies common sense
now drop a bird and a rock from the tower .........
Actually, what he did was roll different size steelballs down a slope which is what the OP intends but because one is filled with liquid the dynamics of fluid may have something to do with the result
Galileo discovered they reach the bottom at the same time so the question is a very good one as it defies common sense
now drop a bird and a rock from the tower .........
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the water filled barrell will roll a little slower until the water inside reaches the same rotational speed as the barrel causing some drag. The time the barrels reached the bottom would depend on two things
1) the length of the ramp. the shorter the ramp teh less effect the drag will have
2) Which one rolled over the GD box with the bird in it
1) the length of the ramp. the shorter the ramp teh less effect the drag will have
2) Which one rolled over the GD box with the bird in it
Clearly the moderators need to open a Physics Section in the General Area of Terb so that members can debate contentious issues in Physics.
Kilgore how can your cat jump from so high and not be hurt
As we have discovered size does not influence rate of fall but if we jumped from such a height .... and why do they always land on their feet
Force = Mass X Acceleration
a 10 lb cat will probably walk( rtun like hell) away you on the other hand would splat.
A cat does not land on its feet ..... the planet rotates to accept the new orientation require by the cat. Any cat owner knows this
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