I rock is dropped of a cliff. 3.4 seconds later, you hear the sound it made hitting the ground. Let the speed of sound equal 340 m/s, and, neglecting air resistance, calculate the height of the cliff.

Question

anonymous · Answer

What I tried was:
$$\huge 3.4s = \frac {h}{340 \frac{m}{s}} + \sqrt{\frac {2h}{9.8\frac {m}{s^2}}}$$

which I was able to simplify to:

$$\huge 3618.85 = 3.13h + 340\sqrt{2y}$$

I don't know how to solve it beyond that, but the answer, 52m, works in that equation.

anonymous · Answer

The h/340 is the portion of the time spent by the sound traveling up the cliff, and the 
sqrt(2h/9.8) is the time spent falling, taken from the equation $$\Delta y = \frac{1}{2}at ^{2}$$

saifoo.khan · Answer

Are u trying to impress us by making fractions?

saifoo.khan · Answer

lol, then keep in mind, we won't we getting impressed by this, Bring something new.

anonymous · Answer

That was a joke; I'm not trying to impress you with fractions. I'm trying to find out how to solve this problem

saifoo.khan · Answer

lol, but u said so.

saifoo.khan · Answer

-Just makin clear-

anonymous · Answer

So you don't know how to solve this, right?

dumbcow · Answer

ok i get 51.7, ......move the (h/340) to other side, then square both sides.....you will end up with a quadratic

anonymous · Answer

Ah, awesome, thanks dumbcow :)

anonymous · Answer

chris is awesome

dumbcow · Answer

btw, where did the y come from ??

dumbcow · Answer

thanks ishaan

anonymous · Answer

oops, that was supposed to be an h