Market Equilibrium Problem and Depth Problem

I have two problems. The first one im not sure how to set up and the second one i got an answer but im not sure if its correct.

1. A fissure in the earth appeared after an earthquake. To measure it vertical depth, a stone was dropped into it and the sound of the stone's impact was heard 4.3 seconds later. The distance (in feet) that the ston fell is given by S- 16t(1)^2, and the distance(in feet) that the sound traveled is given by S = 1090t(2). In the these equations, the distance traveled by the sound and the stone are the same, but their times are not. Using the fact that the total time is 4.3 seconds, find the depth of the fissure.

2.If the supply and demand function for a commodity is given by 4p - q = 42 and (p+2)q = 2100, respectively, find the price that will result in market equilibrium

I got...$9.59

Re: Market Equilibrium Problem and Depth Problem

Quote:

A fissure in the earth appeared after an earthquake. To measure it vertical depth, a stone was dropped into it and the sound of the stone's impact was heard 4.3 seconds later.

let $\displaystyle t$ = time for the stone to reach impact

$\displaystyle d = 16t^2$

$\displaystyle t + \frac{d}{1090} = 4.3$

sub $\displaystyle 16t^2$ for $\displaystyle d$ in the second equation, solve the resulting quadratic equation for $\displaystyle t$ ... then calculate $\displaystyle d = 16t^2$

Re: Market Equilibrium Problem and Depth Problem

Okay, i got it. What about the second problem?

Re: Market Equilibrium Problem and Depth Problem

Quote:

Originally Posted by

**Jperk94** Okay, i got it. What about the second problem?

I'm not familiar with those terms ... sorry.