question on Q.I...fired gun-v-dropped bullet
Maths and statistics discussion, revision, exam and homework help.
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question on Q.I...fired gun-v-dropped bulletFrom studying mechanics (some time ago, i`ll admit) i learned a lot of things, but i think this question on the Stephen Fry panel show Q.I. is so obviously untrue, i don`t know how they could try and pass it of as fact:
a person has a bullet in one hand and a loaded gun in the other .
He drops the bullet, and simultaneously fires the gun at the ground. from 1.5 metres.
Q.I.`s assertion is that both bullets will reach the ground at exactly the same time.
(these people are supposed to be intelligent, and have some intuition)
1) my intuition tells me that this answer is garbage!
2). so does the maths.
for the dropped bullet, you need the weight and the distance fallen.
research (t`internet) tells me that the average speed of a bullet from a handgun is approx 260 metres per second, so the answer Q.I. gives can`t possibly be correct!
(p.s. i can`t be bothered with the maths - i`ve been studying for the past 7 hours and iv`e got burnout)Last edited by Hasufel; 09-07-2012 at 22:51. -
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Re: question on Q.I...fired gun-v-dropped bulletThis. See here.(Original post by Blazy)
Try throwing an object horizontally and dropping an object, both from same height. -
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Re: question on Q.I...fired gun-v-dropped bulletQI is correct because they both fall from the same height of 1.5m, gravity acts on both in the same way and both bullets, for the example to work, weigh the same.
You're getting confused by the fact that one bullet is just being dropped (moving vertically due to gravity) and the other is being shot out of a gun (moving both horizontally due to the shot and vertically due to gravity). -
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Re: question on Q.I...fired gun-v-dropped bulletThey didn't say that.(Original post by Hasufel)
fires the gun at the ground. from 1.5 metres. -
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Re: question on Q.I...fired gun-v-dropped bulletAre you sure that you have worded the question correctly?(Original post by Hasufel)
From studying mechanics (some time ago, i`ll admit) i learned a lot of things, but i think this question on the Stephen Fry panel show Q.I. is so obviously untrue, i don`t know how they could try and pass it of as fact:
a person has a bullet in one hand and a loaded gun in the other .
He drops the bullet, and simultaneously fires the gun at the ground. from 1.5 metres.
Q.I.`s assertion is that both bullets will reach the ground at exactly the same time.
(these people are supposed to be intelligent, and have some intuition)
1) my intuition tells me that this answer is garbage!
2). so does the maths.
for the dropped bullet, you need the weight and the distance fallen.
research (t`internet) tells me that the average speed of a bullet from a handgun is approx 260 metres per second, so the answer Q.I. gives can`t possibly be correct!
(p.s. i can`t be bothered with the maths - i`ve been studying for the past 7 hours and iv`e got burnout)
The gun must be horizontal when fired for it to be true. If the gun is pointing downwards then it is obviously not true.
Have a look here
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Re: question on Q.I...fired gun-v-dropped bulletThis is an amusing question because it comes to you in stages. When you are young you think obviously the dropped bullet will land first. When you get to highschool you learn Physics equations and realise that actually vertical and horizontal motion are independent of each other and so the bullets will land at the same time. When you think about it a bit more, though, you will notice that when you fire a bullet horizontally you are actually firing it away from the Earth and so it will land after the dropped one.
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Re: question on Q.I...fired gun-v-dropped bulletyes - they said that the fired one was fired at the ground!(Original post by raheem94)
Are you sure that you have worded the question correctly?
The gun must be horizontal when fired for it to be true. If the gun is pointing downwards then it is obviously not true.
Have a look here
(so they`re wrong?) -
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Re: question on Q.I...fired gun-v-dropped bulletWouldn't the caliber being used make a difference.
If the caliber is larger then wouldn't the heavier bullet and longer range change things?
I'm far too stupid to figure this out
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Re: question on Q.I...fired gun-v-dropped bulletThe horizontal motion can be seen as unconnected to its vertical motion - this is basic M2 maths. The resultant force for the bullet in both cases is
downwards (assuming no wind resistance). Hence, as they both start with a vertical velocity of zero, they will both fall at the same rate.
This is intuitive. -
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Re: question on Q.I...fired gun-v-dropped bulletHorizontal and vertical motion are independent. If the bullet it fired horizontally then it initially has no vertical speed and the only force acting on it in the vertical plane is gravity. Thus they both take the same amount of time to hit the ground.(Original post by Hasufel)
From studying mechanics (some time ago, i`ll admit) i learned a lot of things, but i think this question on the Stephen Fry panel show Q.I. is so obviously untrue, i don`t know how they could try and pass it of as fact:
a person has a bullet in one hand and a loaded gun in the other .
He drops the bullet, and simultaneously fires the gun at the ground. from 1.5 metres.
Q.I.`s assertion is that both bullets will reach the ground at exactly the same time.
(these people are supposed to be intelligent, and have some intuition)
1) my intuition tells me that this answer is garbage!
2). so does the maths.
for the dropped bullet, you need the weight and the distance fallen.
research (t`internet) tells me that the average speed of a bullet from a handgun is approx 260 metres per second, so the answer Q.I. gives can`t possibly be correct!
(p.s. i can`t be bothered with the maths - i`ve been studying for the past 7 hours and iv`e got burnout) -
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Re: question on Q.I...fired gun-v-dropped bulletHe doesn't fire the gun at the ground, he fires it horizontally.(Original post by Hasufel)
From studying mechanics (some time ago, i`ll admit) i learned a lot of things, but i think this question on the Stephen Fry panel show Q.I. is so obviously untrue, i don`t know how they could try and pass it of as fact:
a person has a bullet in one hand and a loaded gun in the other .
He drops the bullet, and simultaneously fires the gun at the ground. from 1.5 metres.
Q.I.`s assertion is that both bullets will reach the ground at exactly the same time.
(these people are supposed to be intelligent, and have some intuition)
1) my intuition tells me that this answer is garbage!
2). so does the maths.
for the dropped bullet, you need the weight and the distance fallen.
research (t`internet) tells me that the average speed of a bullet from a handgun is approx 260 metres per second, so the answer Q.I. gives can`t possibly be correct!
(p.s. i can`t be bothered with the maths - i`ve been studying for the past 7 hours and iv`e got burnout)
(Well, that's what it's supposed to be, anyway. I don't know what they said on QI.)Last edited by tazarooni89; 09-07-2012 at 23:48. -
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Re: question on Q.I...fired gun-v-dropped bulletCan you please link me to the place where you saw it?(Original post by Hasufel)
yes - they said that the fired one was fired at the ground!
(so they`re wrong?) -
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Re: question on Q.I...fired gun-v-dropped bulletvertical speed is independent of horizontal speed (or so I was taught in physics.) So just because the bullet is moving at a great horizontal speed, it will still move at the same vertical speed as the bullet that is just dropped.
