Problem #3 Evaluate Cosine with calculator
(Modeling) Measuring Speed by Radar Any offset
between a stationary radar gun and a moving target
creates a "cosine effect" that reduces the radar read-
ing by the cosine of the angle between the gun and the
vehicle. That is, the radar speed reading is the product
of the actual speed and the cosine of the angle. (Source:
Fischetti, M., “Working knowledge," Scientific American.)
Find the radar readings, to the nearest unit, for
Auto A and Auto B shown in the figure.
Radar gun
Auto A
10° angle
Actual speed: 70 mph
Auto B
20 angle
Actual speed: 70 mph