Question

A state patrol officer saw a car start from rest at a highway​ on-ramp. She radioed ahead to another officer 20 mi along the highway. When the car reached the location of the second officer 19 min​ later, it was clocked going 60​ mi/hr. The driver of the car was given a ticket for exceeding the 60​ mi/hr speed limit. Why can the officer conclude that the driver exceeded the speed​ limit?

Answer 1

We know from the basic speed distance relation that

`Speed=(Distance)/(Time)`

Since the car started from rest and it covered the distance between the 2 officer's in 19 minutes we have speed of the car

`Speed=(Distance)/(Time)\\\\Speed=(20)/((19)/(60))=63.16mph`

Which clearly exceeds the limit of
`60(mi)/(hr)`