kallend 2,026 #26 January 29, 2006 QuoteQuoteFinally, since there is no air on the Moon, and hence no terminal velocity, are you implying that Newton's 3rd law doesn't apply there? Why do you use NewtonIII in a case where is no reaction? Reaction is going to happen when the object touches the surface. NewtonIII is the case where an object is not the surface of the Moon. NewtonII should be use with an object over the Moon surface or moving with the 1st or 2st orbiting speed of the Moon. Of course there's reaction. The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. Equal and opposite. Air resistance is NOT the equal and opposite reaction to gravity. Your explanation is incorrect.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
phoenixlpr 0 #27 January 29, 2006 ***Of course there's reaction. The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. Equal and opposite. Air resistance is NOT the equal and opposite reaction to gravity. Your explanation is incorrect. Quote I don't think so. The question was the terminal velocity where the magnitude of the forces are equal and the direction is opposite. Quote Share this post Link to post Share on other sites happythoughts 0 #28 January 29, 2006 terminal velocity = speed - drag speed is gravitational attraction. heavier objects go faster. drag (none in a vacuum) is determined by air friction on the surface of the object and its shape. a skydiver with an open parachute and one with a closed parachute weigh the same but fall at different speeds. (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) Quote Share this post Link to post Share on other sites kallend 2,026 #29 January 29, 2006 Quote***Of course there's reaction. The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. Equal and opposite. Air resistance is NOT the equal and opposite reaction to gravity. Your explanation is incorrect. Quote I don't think so. The question was the terminal velocity where the magnitude of the forces are equal and the direction is opposite. That is not Newton's 3rd Law, though. You misunderstand the Law.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites phoenixlpr 0 #30 January 29, 2006 ??? OK. I was not 100% correct. I've left the the gravitational force by the skydiver to the earth. Quote Share this post Link to post Share on other sites Trae 1 #31 January 30, 2006 in reply to "The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. " ............................. Doea this mean that as skydivers we are dragging the earth into a new orbit? Because wingsuiters stay in the air longer does that mean they are dragging the earth more than freeflyers? Because most skydiving is done in the day-time are we slowly dragging the earth into the sun? Quote Share this post Link to post Share on other sites MooChooser 0 #32 January 30, 2006 Its not only large objects that attract. Everything attracts everything else. Its just that huge objects like the earth dont move as much toward you as you do towards it. Infact its not the earths gravity that pulls you down, its the sum of the gravity of every atom that makes up the earth pulling on each atom in your body and vice versa. Gravity is a very weak force as far as forces in the universe go so it takes something big to make it noticable. Quote Share this post Link to post Share on other sites Weichkeks 0 #33 January 30, 2006 QuoteBecause most skydiving is done in the day-time are we slowly dragging the earth into the sun? ROTFL This made my day Quote Share this post Link to post Share on other sites labrys 0 #34 January 31, 2006 QuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. Drop a bowling ball and a feather in a swimming pool and see which falls faster Owned by Remi #? Quote Share this post Link to post Share on other sites kallend 2,026 #35 January 31, 2006 QuoteQuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. ] Dunno where YOU live, but it's a gas here in Illinois. I suspect you mean "fluid".... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites labrys 0 #36 January 31, 2006 Ummmm... yeah. 2 beat-downs in one week means I'm posting too often and thinking too little.Owned by Remi #? Quote Share this post Link to post Share on other sites happythoughts 0 #37 January 31, 2006 I think Sangiro needs to put this up as a Sticky. For this forum, it would reduce his bandwidth by 30%. Quote Share this post Link to post Share on other sites jgorm 0 #38 February 1, 2006 Quote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. Quote Share this post Link to post Share on other sites kallend 2,026 #39 February 1, 2006 QuoteQuote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. If I put on my physicist hat I would have to nitpick the statement, since it's acceleration, not fallrate, that would be constant, and even then only at a specified distance from the center of the attracting planet/moon/star...... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites MooChooser 0 #40 February 1, 2006 QuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Quote Share this post Link to post Share on other sites kallend 2,026 #41 February 1, 2006 QuoteQuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Yes, and I am wearing my physicist's hat today, so there's no inconsistency.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites Prev 1 2 Next Page 2 of 2 Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0 Go To Topic Listing
happythoughts 0 #28 January 29, 2006 terminal velocity = speed - drag speed is gravitational attraction. heavier objects go faster. drag (none in a vacuum) is determined by air friction on the surface of the object and its shape. a skydiver with an open parachute and one with a closed parachute weigh the same but fall at different speeds. (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) Quote Share this post Link to post Share on other sites
kallend 2,026 #29 January 29, 2006 Quote***Of course there's reaction. The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. Equal and opposite. Air resistance is NOT the equal and opposite reaction to gravity. Your explanation is incorrect. Quote I don't think so. The question was the terminal velocity where the magnitude of the forces are equal and the direction is opposite. That is not Newton's 3rd Law, though. You misunderstand the Law.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites phoenixlpr 0 #30 January 29, 2006 ??? OK. I was not 100% correct. I've left the the gravitational force by the skydiver to the earth. Quote Share this post Link to post Share on other sites Trae 1 #31 January 30, 2006 in reply to "The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. " ............................. Doea this mean that as skydivers we are dragging the earth into a new orbit? Because wingsuiters stay in the air longer does that mean they are dragging the earth more than freeflyers? Because most skydiving is done in the day-time are we slowly dragging the earth into the sun? Quote Share this post Link to post Share on other sites MooChooser 0 #32 January 30, 2006 Its not only large objects that attract. Everything attracts everything else. Its just that huge objects like the earth dont move as much toward you as you do towards it. Infact its not the earths gravity that pulls you down, its the sum of the gravity of every atom that makes up the earth pulling on each atom in your body and vice versa. Gravity is a very weak force as far as forces in the universe go so it takes something big to make it noticable. Quote Share this post Link to post Share on other sites Weichkeks 0 #33 January 30, 2006 QuoteBecause most skydiving is done in the day-time are we slowly dragging the earth into the sun? ROTFL This made my day Quote Share this post Link to post Share on other sites labrys 0 #34 January 31, 2006 QuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. Drop a bowling ball and a feather in a swimming pool and see which falls faster Owned by Remi #? Quote Share this post Link to post Share on other sites kallend 2,026 #35 January 31, 2006 QuoteQuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. ] Dunno where YOU live, but it's a gas here in Illinois. I suspect you mean "fluid".... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites labrys 0 #36 January 31, 2006 Ummmm... yeah. 2 beat-downs in one week means I'm posting too often and thinking too little.Owned by Remi #? Quote Share this post Link to post Share on other sites happythoughts 0 #37 January 31, 2006 I think Sangiro needs to put this up as a Sticky. For this forum, it would reduce his bandwidth by 30%. Quote Share this post Link to post Share on other sites jgorm 0 #38 February 1, 2006 Quote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. Quote Share this post Link to post Share on other sites kallend 2,026 #39 February 1, 2006 QuoteQuote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. If I put on my physicist hat I would have to nitpick the statement, since it's acceleration, not fallrate, that would be constant, and even then only at a specified distance from the center of the attracting planet/moon/star...... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites MooChooser 0 #40 February 1, 2006 QuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Quote Share this post Link to post Share on other sites kallend 2,026 #41 February 1, 2006 QuoteQuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Yes, and I am wearing my physicist's hat today, so there's no inconsistency.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites Prev 1 2 Next Page 2 of 2 Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0
phoenixlpr 0 #30 January 29, 2006 ??? OK. I was not 100% correct. I've left the the gravitational force by the skydiver to the earth. Quote Share this post Link to post Share on other sites
Trae 1 #31 January 30, 2006 in reply to "The reaction to the gravitational force of the Earth on a skydiver is the gravitational force exerted by the skydiver on the Earth. " ............................. Doea this mean that as skydivers we are dragging the earth into a new orbit? Because wingsuiters stay in the air longer does that mean they are dragging the earth more than freeflyers? Because most skydiving is done in the day-time are we slowly dragging the earth into the sun? Quote Share this post Link to post Share on other sites
MooChooser 0 #32 January 30, 2006 Its not only large objects that attract. Everything attracts everything else. Its just that huge objects like the earth dont move as much toward you as you do towards it. Infact its not the earths gravity that pulls you down, its the sum of the gravity of every atom that makes up the earth pulling on each atom in your body and vice versa. Gravity is a very weak force as far as forces in the universe go so it takes something big to make it noticable. Quote Share this post Link to post Share on other sites
Weichkeks 0 #33 January 30, 2006 QuoteBecause most skydiving is done in the day-time are we slowly dragging the earth into the sun? ROTFL This made my day Quote Share this post Link to post Share on other sites
labrys 0 #34 January 31, 2006 QuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. Drop a bowling ball and a feather in a swimming pool and see which falls faster Owned by Remi #? Quote Share this post Link to post Share on other sites
kallend 2,026 #35 January 31, 2006 QuoteQuoteSerious question, why do we fall at different rates? At school we where taught that everything falls at the same rate The point that everything falls at the same rate without resistance has been well made already..but if you want a good visual think about the fact that our atmosphere is a liquid. ] Dunno where YOU live, but it's a gas here in Illinois. I suspect you mean "fluid".... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
labrys 0 #36 January 31, 2006 Ummmm... yeah. 2 beat-downs in one week means I'm posting too often and thinking too little.Owned by Remi #? Quote Share this post Link to post Share on other sites
happythoughts 0 #37 January 31, 2006 I think Sangiro needs to put this up as a Sticky. For this forum, it would reduce his bandwidth by 30%. Quote Share this post Link to post Share on other sites
jgorm 0 #38 February 1, 2006 Quote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. Quote Share this post Link to post Share on other sites
kallend 2,026 #39 February 1, 2006 QuoteQuote (this "fallrate is equal in a vacuum" thing has to be the most mis-quoted statement that exists.) In a vacuum you will fall at the same rate with your parachute open or not. I agree that it gets misquoted by leaving off the vacuum part. If I put on my physicist hat I would have to nitpick the statement, since it's acceleration, not fallrate, that would be constant, and even then only at a specified distance from the center of the attracting planet/moon/star...... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
MooChooser 0 #40 February 1, 2006 QuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Quote Share this post Link to post Share on other sites
kallend 2,026 #41 February 1, 2006 QuoteQuoteIf I put on my physicist hat I would have to nitpick the statement I think you just did. Yes, and I am wearing my physicist's hat today, so there's no inconsistency.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
