I've forgotten my O-level physics
May 30th 2011, 5:04 am
#1
Hit 16's
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I've forgotten my O-level physics
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. The forward motion of an object has no effect on the pull of gravity.
This is a "fact" from today's BBC website. Can't be true
This is a "fact" from today's BBC website. Can't be true
May 30th 2011, 5:09 am
#2
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Re: I've forgotten my O-level physics
Ok I cheated and used the wise and mighty Google but:
"Yes, its true. The bullet fired from the gun will travel with a projectile motion. It is nothing but the resultant of two motion, the horizontal motion of the bullet imposed by the gun and the gravity pull. Due to this two motions the path of the bullet will be a curvilinear motion and the height of the bullet will descend. But the gravitational force is constant, it will bring down the bullet same time as which it will take to bring down the bullet from the same height from rest. Does in both cases, the bullet will hit the ground at same time"
and now the cavaet (also courtesy og Google):
"Physics questions are usually formed by ommiting forces that will have a small effect upon the outcome. In your example the force of air resistance has been taken out, so the only force acting up on the bullet whilst in motion is a result of gravity. If air resistance was taken into account the result would be much different"
I was going to try and blag it like I knew but if I was challenged the game would have been up....
"Yes, its true. The bullet fired from the gun will travel with a projectile motion. It is nothing but the resultant of two motion, the horizontal motion of the bullet imposed by the gun and the gravity pull. Due to this two motions the path of the bullet will be a curvilinear motion and the height of the bullet will descend. But the gravitational force is constant, it will bring down the bullet same time as which it will take to bring down the bullet from the same height from rest. Does in both cases, the bullet will hit the ground at same time"
and now the cavaet (also courtesy og Google):
"Physics questions are usually formed by ommiting forces that will have a small effect upon the outcome. In your example the force of air resistance has been taken out, so the only force acting up on the bullet whilst in motion is a result of gravity. If air resistance was taken into account the result would be much different"
I was going to try and blag it like I knew but if I was challenged the game would have been up....
May 30th 2011, 5:10 am
#3
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Re: I've forgotten my O-level physics
It appears this is true! unless it hits something obviously!
http://answers.yahoo.com/question/in...0202101AAo3EXm
http://answers.yahoo.com/question/in...0202101AAo3EXm
May 30th 2011, 5:18 am
#4
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Re: I've forgotten my O-level physics
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. The forward motion of an object has no effect on the pull of gravity.
This is a "fact" from today's BBC website. Can't be true
This is a "fact" from today's BBC website. Can't be true
now, the one I don't believe is the blackberry advert saying that ants can not/do not sleep.
May 30th 2011, 5:41 am
#5
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Re: I've forgotten my O-level physics
True - the Mythbusters (Discovery Channel) have tested this - I saw the episode a few weeks ago.
May 30th 2011, 6:44 am
#6
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Re: I've forgotten my O-level physics
next up, in a vacuum a feather and a tennis ball will fall and hit the ground at the same time.
but I guess the question is which weighs more a ton of feathers or a ton of lead?
but I guess the question is which weighs more a ton of feathers or a ton of lead?
May 30th 2011, 7:02 am
#7
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Re: I've forgotten my O-level physics
"Queen ants dozily dream, while worker ants are forced to get by taking power naps, the first study of the sleeping habits of ants has revealed.
Queen fire ants fall into relatively long, deep sleeps and kip for an average of nine hours every day. By contrast, workers sleep just half as much and get to rest by taking hundreds of short power naps. This division of rest may help explain why queens live for years, while worker ants typically only live for months. It also ensures that enough worker ants are awake at any one time to protect and serve the colony"
http://news.bbc.co.uk/earth/hi/earth...00/8100876.stm
May 30th 2011, 7:34 am
#8
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Re: I've forgotten my O-level physics
tut tutthey are both acting on the same object, hence not acting independently... thats why the trajectory of the bullet is curvlinear, rather that totally horizontal or totally vertical.
back of the class for you
May 30th 2011, 8:04 am
#9
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Re: I've forgotten my O-level physics
- the force of gravity is totally independent of the horizontal force from the explosion acting on the bullet. Gravity doesn't switch off is my point. You can perform the calculations in each vector independently or together and get the same answer to the question - which really was, does the time taken to hit the ground differ.
May 30th 2011, 8:46 am
#10
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Re: I've forgotten my O-level physics
I have never been put to the back of a fizzics class - the force of gravity is totally independent of the horizontal force from the explosion acting on the bullet. Gravity doesn't switch off is my point.
You can perform the calculations in each vector independently or together and get the same answer to the question - which really was, does the time taken to hit the ground differ.
- the force of gravity is totally independent of the horizontal force from the explosion acting on the bullet. Gravity doesn't switch off is my point. You can perform the calculations in each vector independently or together and get the same answer to the question - which really was, does the time taken to hit the ground differ.
let me win one internet battle
May 30th 2011, 8:50 am
#11
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Re: I've forgotten my O-level physics
May 30th 2011, 8:55 am
#13
Hit 16's
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Re: I've forgotten my O-level physics
So, another typical, bloody BBC lie:
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
May 30th 2011, 9:11 am
#14
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Re: I've forgotten my O-level physics
So, another typical, bloody BBC lie:
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
Would it still make a difference?
I've heard this one debated before, and it is true as long as you word it correctly. Similar to the tree falling in the woods, nobody around to hear it, does it make a sound/noise.
May 30th 2011, 9:12 am
#15
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Re: I've forgotten my O-level physics
So, another typical, bloody BBC lie:
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
A bullet fired horizontally from a gun, and a second bullet dropped by hand from the same height as the gun, will both hit the ground at the same time. But only in a vacuum.
So, in fact, an impossibility--coz in order to get to a vacuum that big, you'd have to be in space, and the bullet would burn up getting back into the Earth's atmosphere.
Last edited by weasel central; May 30th 2011 at 9:14 am. Reason: science shit