What a delightful little problem !
Here's how I see it:
When 'C' is touched to 'A', charge flows to 'C' until the two of them are equally charged. So now, 'A' has half of its original charge, and 'C' has the other half.
Then, when 'C' is touched to 'B', charge flows to it until the two of <u>them</u> are equally charged. How much is that ? Well, just before they touch, 'C' has half of an original charge, and 'B' has a full one, so 1/4 of an original charge flows from 'B' to 'C', and then each of them has 3/4 of an original charge.
To review what we have now: 'A' has 1/2 of its original charge, and 'B' has 3/4 of it.
The force between any two charges is:
F = (a constant) x (one charge) x (the other one) / (the distance between them)².
For 'A' and 'B', the distance doesn't change, so we can leave that out of our formula.
The original force between them was 3 = (some constant) x (1 charge) x (1 charge).
The new force between them is F = (the same constant) x (1/2) x (3/4) .
Divide the first equation by the second one, and you have a proportion:
3 / F = 1 / ( 1/2 x 3/4 )
Cross-multiply this proportion:
3 (1/2 x 3/4) = F
F = 3/2 x 3/4 = 9/8 = <em>1.125 newton</em>.
That's my story, and I'm sticking to it.
KE = 1/2 mv^2 is the relationship betwee mass and kinetic energy
Answer:
Length, l = 3.57 meters
Explanation:
It is given that,
Area of cross-section of gold wire, 
Resistivity of gold wire, 
Resistance, R = 0.001 ohms
Resistance in terms of length and area is given by :
l = 3.57 meters
So, the length of the wire is 3.57 meters. Hence, this is the required solution.
Momentum = (mass) x (speed)
Mass is constant, so the rate of change of momentum is
(mass) x (rate of change of speed) .
But (rate of change of speed ) is just acceleration.
So the rate of change of momentum is (mass) x (acceleration).
But (mass) x (acceleration) is Force.
So Force is the rate of change of momentum. Verrrrrrrry interesting !
In this problem, Force = (40 kg) x (9 m/s²) = 360 newtons.
One 'Newton' is one kilogram-meter per second² .
Unit of momentum is (kilogram)-(meter per second), so 'newton'
is also a unit of time rate of change of momentum.
Rate of change of momentum is 360 momentum units per second.
Answer:
Explanation:
To find Depth D of lake we must need to find the time taken to hit the water.So we use equation of simple motion as:
Δx=vit+(1/2)at²
As we have find the time taken now we need to find the final velocity vf from below equation as
So the depth of lake is given by:
first we need to find total time as
t=3.0-1.01 =1.99 s
