A New Jersey state trooper has set up a powerful advanced radar gun and binoculars at a location 4 miles?

Question

from a long straight section of the turnpike. While looking perpendicular to the turnpike he observes a car passing a milepost at high rate of speed. By the time he gets the radar gun pointed at the car the readings show that the car is 5 miles distant and the distance from the officer to the car is changing at the rate of 54 miles per hour. How fast is the car traveling down the turnpike at the instant the reading on the radar gun was taken?

Answer 1

77.5 mph
54 / cos(.8)

Answer 2

The pont is moot because the officer's unapproved speed detecting system would never hold up court. The car might as well be going 170mph.