College Algebra Project Questions

[Bae]

I'm going to try and make the intro short, so you don't have to read all the "blah":
The minimum radius (in feet)that should be used is given by r= 0.334s^2 and the distance, d, needed to stop a car is given by d= 0.05 s^2 +1.1 s, where s is the expected speed of traffic in miles per hour. Please answer the following questions.

I have already done a. & b. but I'm stuck on c.-e.
C. How fast can you go around the curve with a radius of 450 feet?
I began plugging things into the formulas given... so this is where I'm at:(r=450) s(450/.334) ...i just don't know if that's the right set up?

And then D. I'm supposed to use my answer from C. to find the distance needed to stop the car using the formula d= 0.05 s^2 +1.1 s?

And finally, e, What speed limit should be posted on the road where the drivers drive around the curve and have 85 feet to come to a stop?

Please & Thank you for the help!

 

[stapel]

The minimum radius (in feet)that should be used is given by r= 0.334s^2 and the distance, d, needed to stop a car is given by d= 0.05 s^2 +1.1 s, where s is the expected speed of traffic in miles per hour. Please answer the following questions.

I have already done a. & b. but I'm stuck on c.-e.
C. How fast can you go around the curve with a radius of 450 feet?
I began plugging things into the formulas given... so this is where I'm at:(r=450) s(450/.334) ...i just don't know if that's the right set up?

I don't know what you're doing here...? Instead, try plugging "450" in for "r" in the posted equation, and then solving for the value of "s".

And then D. I'm supposed to use my answer from C. to find the distance needed to stop the car using the formula d= 0.05 s^2 +1.1 s?

Take the solution from (C) and plug the (positive) value in for "s" in the "distance" equation. Simplify to find "d".

And finally, e, What speed limit should be posted on the road where the drivers drive around the curve and have 85 feet to come to a stop?

Plug "85" in for "d", and solve the resulting quadratic equation for the value of "s".