The equation s =square root 30fd can be used to find the car's speed s in mph given the length d in feet of a skid mark and the friction factor f of the road. Police measured a skid mark of 90 feet on a dry concrete road. If the speed limit is 35mph, was the car speeding? Explain

Respuesta :

Answer:

Yes, the car was speeding the speed limit.

Step-by-step explanation:

The given equation to find the car's speed, s (in mph), is

[tex]s=\sqrt{30fd}[/tex]

where, d is the length of the skid and f is the friction factor.

Police measured a skid mark of 90 feet, so d=90

As the road is dry and of concrete, therefore the friction factor, f=0.8.

So, the speed of the car

[tex]s=\sqrt{30\times0.8\times90} = 46.48[/tex] mph

The speed of the car is 46.48 mph which is more than the speed limit of 35 mph.

Hence, the car was speeding the speed limit.