Was Galileo correct in his theory?
2006-09-08 10:22:00 · 9 answers · asked by John G 5 in Science & Mathematics ➔ Physics
Didn't Galileo test this theory by throwing things off the Tower of Pisa or something?
2006-09-08 10:27:42 · update #1
actually, a feather does NOT have more surface area than a bowling ball. the difference is that the ratio of surface area to mass is greater for the feather. incidently, initial acceleration for the feather is the same as for the bowling ball. the reason the feather ultimately falls slower happens because the mass to surface area ratio is such that the terminal velocity of the feather (the top speed a given object can fall at) is less than the terminal velocity of the bowling ball. as has been said, in a vacuum they would both fall at the same speed. WHY? because in a vacuum the surface area doesn't make a difference... there's no air to cause drag and resist the downward motion of the feather OR the bowling ball. in otherwords, the terminal velocity of an object in vacuum is "theoretically" infinite. in the real world, however, it CAN'T be infinite, because you're going to collide with the object causing the gravitational field before too long.
2006-09-08 10:30:15 · answer #1 · answered by promethius9594 6 · 1⤊ 0⤋
Sir: Without any physical atmosphere present, all objects would fall at the same speed towards the earth's core due to gravity. However air covers the planet and therefore is a form of Resistance by which I mean there is matter bewteen the feather/bowling ball and the ground...the matter is made of the ingridents of air. Due to the shape of the bowling ball it does hit the matter and because it is a smooth rounded object, it slips through the air... it spreads across the ball as the ball drops, with little resisentence and friction as it falls. But the feather is designed to float, to trap air underneath the wing's feathers and to push against the density of the air in order to rise up and fly, therefore the microscopic fronds of the feather interfere with the air molecules, trapping them and causing them to push back on the feather increasing resistence and causing lift and the feather gently rocks side to side as it falls to the ground. It may appear that there is a difference in speeds and that's because items with no ability to catch air like a parachute or a hot air balloon (shape) an object like a bowling ball or a rock just falls... while a feather (bird) can float on the air, and glide or fly ... Galileo proved that two objects of equal weight will fall at the same speed, but unequal weight will also fall at the same speed as long as they're of similar nature...bowling ball is not similar to a feather so the air pushes back more on the feather and it drifts down while the ball zips to the ground...
2006-09-08 10:42:05 · answer #2 · answered by Anonymous · 1⤊ 0⤋
A feather falls slower because it has more surface area and since there are more air molecules underneath it, they all push upward on the feather, causing it to fall slower.
However, if you had both objects in a vacuum, they would fall at the same speed. This has been verified by experiments.
This is Newton's law of gravitation, not Galileo, by the way ;-)
2006-09-08 10:25:50 · answer #3 · answered by phosphoricx3 2 · 2⤊ 0⤋
They do not fall at the same speed but with the same accelration, if you neglect air resistance. Air resistance is based on how fast you are going and how much the material weighs and how big the material's cross sectional area is. A bowling ball has a much larger mass to cross sectional area ratio than a feather, so fall faster as the effect of air resistance on a bowling ball is negliable compared to the effect of air resistance on a feather.
2006-09-08 10:29:26 · answer #4 · answered by msi_cord 7 · 2⤊ 0⤋
They did this experiment on the moon. Guess what? The feather fell as fast as the bowling ball. Chalk one up for Galileo.
2006-09-08 10:27:40 · answer #5 · answered by Amphibolite 7 · 2⤊ 0⤋
Objects falling in a vacuum fall at the same speed. The basis for your question is fundamentally incorrect.
2006-09-08 10:25:36 · answer #6 · answered by Ecobuckeye 2 · 1⤊ 0⤋
Your premise is not true. There is air friction that has a different effect on different objects. In a vacuum they would fall at the same speed.
2006-09-08 10:28:56 · answer #7 · answered by Barkley Hound 7 · 2⤊ 0⤋
Simply, in two words... There is air resisance which changes by the weight of the object. When the weight decrese the air resistance increse reducing its speed!
Thats all.. simple aint it?! :D
2006-09-08 11:32:35 · answer #8 · answered by Anonymous · 1⤊ 0⤋
Air friction. Go to the source, click on the "Video libs." link, then the "Apollo 15 Clips" link and view the "Hammer and the Feather" video.
2006-09-08 10:24:37 · answer #9 · answered by campbelp2002 7 · 2⤊ 0⤋