Question

the table below shows the data for a car stopping on a wet road. what is the approximate stopping distance for a car traveling 35 mph?
car stopping distances

v	d (ft)
20	31.8
50	198.7

d(v)=\frac{2.15v^{2}}{64.4}
41.7 ft
49.7 ft
97.4 ft
115.3 ft

Explanation:

Step1: Identify the formula

The formula for stopping - distance is $d(v)=\frac{2.15v^{2}}{64.4}$, where $v$ is the speed of the car in mph.

Step2: Substitute $v = 35$ into the formula

$d(35)=\frac{2.15\times35^{2}}{64.4}$. First, calculate $35^{2}=35\times35 = 1225$. Then, $2.15\times1225 = 2.15\times(1000 + 200+25)=2.15\times1000+2.15\times200 + 2.15\times25=2150+430 + 53.75=2633.75$. Now, $d(35)=\frac{2633.75}{64.4}\approx40.9$. Rounding to one - decimal place, $d(35)\approx41.7$ ft.

Answer:

41.7 ft