halp w/ physics HW plox.

Someone help me out w/ my physics HW and i'll pst some ascii porn for you or something fuck i dunno.

A man drops a stone from a high bridge and hears it strike the water below exactly 7 s later. (Assume the speed of sound is 340 m/s.).

Calculate the exact distance (from the man to the water).

VARIABLES to be used:

'a' is the acceleration due to gravity (assumed to be 9.8m/(s^2))

't' is the falling time of the object dropped by the man (falling between the man and the water).

Note that 't' IS NOT equal to 7s (because 7 seconds is the amount of time between when the man lets go of the rock and when he hears the sound of the rock hitting the water (so you need to take into account the 7s includes the time it takes for the sound waves from the rock hitting the water to travel to the man)).

Therefore, to take away any possible confusion here, i will now use 'T' to denote the TOTAL time (7s).

'd' is simply the distance between the man and the water.

's' is the speed of sound (assumed to be 340m/s).

Work:

The equation that relates falling distance and time is:
d = (1/2)*a*t^2

I reworked the equation to put 't' in terms of 'd':
t = (2d/a)^(1/2)

Then I added the time it will take the sound waves to traverse the distance between the man and the water (the equation for that would be: d/s) to both sides of the equation with 't' in terms of 'd' to get this equation:

t + d/s = (2d/a)^(1/2) + d/s =
T = (2d/a)^(1/2) + d/s <<<<<<< THIS LINE IS AS FAR AS I HAVE GOTTEN

To, pretty much, i have the values of all the variables except 'd' (which is equivalent to the answer of the problem).

The main issue is, how do I work this equation into one in the format of "d = blah blah blah"?:

T = (2d/a)^(1/2) + d/s

Is there a problem in how i got that equation (I don't think so)? How do I rework that equation?

thx dood

Top 10 Excuses for Not Turning in Math Homework

10. It's Isaac Newton's birthday.
9. I couldn't decide whether i is the square root of -1 or i are the square root of -1.
8. I accidently divided by 0 and my paper burst into flames.
7. It's stuck inside a Klein bottle.
6. I could only get arbitrarily close to my textbook.
5. I had too much pi and got sick.
4. Someone already published it, so I didn't bother to write it up.
3. A four-dimensional dog ate it.
2. I have a solar calculator and it was cloudy.
1. There wasn't enough room to write it in the margin.