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The stopping distance on wet pavement at 20mph is about 60feet. The stopping distance at 30mph is 120feet. What would you estimate the stopping distance is at 40mph? Construct a formula

User Christofer Eliasson
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1 Answer

23 votes
23 votes

Answer:


y = 6x - 60 --- formula

The stopping distance at 40mph is 180ft

Explanation:

Given


(x,y) = (20,60)


(x,y) = (30,120)

Solving (a): Construct a formula

Calculate the slope (m)


m = (y_2 - y_1)/(x_2 - x_1)


m = (120 - 60)/(30-20)


m = (60)/(10)


m=6

So, the equation is:


y = m(x - x_1) + y_1


y = 6(x - 20) + 60

Open bracket


y = 6x - 120 + 60


y = 6x - 60

Hence, the formula to use is:
y = 6x - 60

Solving (b): y, when x = 40


y = 6x - 60


y = 6 * 40 - 60


y = 180

User REDDY PRASAD
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