stopping distance

Question

A typical car’s stopping distance, in feet, on wet pavement can be approximated by the expression 00.8s² + 0.24s - 7.10, where s is the speed of the car, in miles per hour (mph), before breaking and

60≤ s ≤80 miles per hour. Use the expression to approximate the car’s stopping distance on wet pavement if the speed of the car before breaking is 72 mph.

Answer 1

Lulu,

 

The stopping distance is d = 0.8*s^2 + 0.24*s -7.1

 

For speed of 72 miles per hr substitute the value for s = 72 in the equation

 

d = 0.8*72(^2) + 0.24*72 -7.1 = 4157.38 ft

 

PS: Check if the coefficient of S^2 term is 0.8 or 0.08 adn adjust accordingly.