Time and Distance problem

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Time and Distance problem

by mahen_gupta » Thu Feb 17, 2011 4:38 am
If two people start from point A and Point B towards each other and arrive at 2 points in "a" and "b" hour respectively after having met then

A's speed/ B's speed = sqrt(a)/sqrt(b).

Could you please explain?
Last edited by mahen_gupta on Thu Feb 17, 2011 7:22 am, edited 1 time in total.
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by ankur.agrawal » Thu Feb 17, 2011 6:04 am
mahen_gupta wrote:If two people start from point A and Point B towards each other and arrive at 2 points in "a" and "b" hour respectively after having met then

A's speed/ B' speed = sqrt(b)/sqrt(b).

Could you please explain?
sqrt(b)/sqrt(b)=1. Is this what u r asking? Where did u read this.

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by mahen_gupta » Thu Feb 17, 2011 7:21 am
Sorry...Cut Paste error...

If two people start from point A and Point B towards each other and arrive at 2 points in "a" and "b" hour respectively after having met then

A's speed/ B's speed = sqrt(a)/sqrt(b).

Could you please explain, how?

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by Anurag@Gurome » Thu Feb 17, 2011 7:13 pm
mahen_gupta wrote:If two people start from point A and Point B towards each other and arrive at 2 points in "a" and "b" hour respectively after having met then

A's speed/ B's speed = sqrt(a)/sqrt(b).

Could you please explain?
A and B are points.
How can they have speed?
I am assuming you are talking about the speeds of persons starting from A and B.
Let them be denoted by P1 and P2 and let their speeds be x and y respectively.
So P2 is reaching point A in "a" hours after meeting P1.
Also, P1 is reaching point B in "b" hours after meeting P2.
Let the distance from A to B be d.
Time after which they meet each other is d/(x+y).
In this time, P1 has travelled dx/(x+y) distance and P2 has travelled dy(x+y) distance.
So P2 needs to cover dx/(x+y) distance and P1 needs to cover dy(x+y) distance.
So {dx/(x+y)}/y = a and {dy/(x+y)}/x = b.
Or taking their ratios, [{dx/(x+y)}/y]/[{dy/(x+y)}/x] = a/b.
Or (x^2)/(y^2) = a/b.
Or x/y = sqrt(a)/sqrt(b).
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by sanju09 » Fri Feb 18, 2011 12:42 am
Anurag@Gurome wrote:
mahen_gupta wrote:If two people start from point A and Point B towards each other and arrive at 2 points in "a" and "b" hour respectively after having met then

A's speed/ B's speed = sqrt(a)/sqrt(b).

Could you please explain?
A and B are points.
How can they have speed?
I am assuming you are talking about the speeds of persons starting from A and B.
Let them be denoted by P1 and P2 and let their speeds be x and y respectively.
So P2 is reaching point A in "a" hours after meeting P1.
Also, P1 is reaching point B in "b" hours after meeting P2.
Let the distance from A to B be d.
Time after which they meet each other is d/(x+y).
In this time, P1 has travelled dx/(x+y) distance and P2 has travelled dy(x+y) distance.
So P2 needs to cover dx/(x+y) distance and P1 needs to cover dy(x+y) distance.
So {dx/(x+y)}/y = a and {dy/(x+y)}/x = b.
Or taking their ratios, [{dx/(x+y)}/y]/[{dy/(x+y)}/x] = a/b.
Or (x^2)/(y^2) = a/b.
Or x/y = sqrt(a)/sqrt(b).
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