SOLUTION: 1.) A rocket is 1 mile above the earth 30 seconds after lifting off. The rocket is 5 miles above the earth after 2.5 minutes. a) Write an equation that represents this situatio

Algebra ->  Graphs -> SOLUTION: 1.) A rocket is 1 mile above the earth 30 seconds after lifting off. The rocket is 5 miles above the earth after 2.5 minutes. a) Write an equation that represents this situatio      Log On


   



Question 828174: 1.) A rocket is 1 mile above the earth 30 seconds after lifting off. The rocket is 5 miles above the earth after 2.5 minutes.
a) Write an equation that represents this situation.
b) What does the slope represent in this situation? The y-intercept?
P.S. Could you also show me how you got the answers? Thanks!

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
At liftoff the rocket is at ground level, 0 miles above earth's surface.
After 30 seconds, it is 1 mile above earth's surface.

a) The average upwards speed of the rocket during the first 30 seconds (0.5 minutes) is
1mile%2F%220.5+minutes%22=2miles per minute.
The average upwards speed of the rocket during the next 2 minutes (between 30 seconds and 2.5 minutes after liftoff) in miles per minute is
%285-1%29%2F%282.5-0.5%29=4%2F2=2.
It may not be scientifically sound to assume that the speed was 2 miles per minute at all times, but my guess is that your teacher intended exactly that.
So the height h of the rocket (in miles), as a function of time t (in minutes) since liftoff is
h%28t%29=2t
If you called the height in miles y and the time in minutes x ,
then the equation would be y=2x .
Either way, the function is a linear function.
Its graph is a straight line through the origin.
I would graph it only for t%3E=0 because we do not know where that rocket was before liftoff (for t%3C0 ).


b) The slope in y=2x%2B0 is 2 miles per minute and represents the speed of the rocket.
The y-intercept is 0 miles, because the graph crosses the y-axis at y=0 .
The y-intercept represents the height of the rocket at liftoff: 0 miles above earth.