Question

sat #1 reading & writing - part 2
a radar speed gun sends out a microwave signal at a known frequency towards a moving vehicle. when the signal reflects off the vehicle, it returns at a modified frequency because of the doppler effect. the difference between the original and return frequencies allows the speed gun to ______ the precise velocity of the vehicle.
which choice completes the text with the most logical and precise word or phrase?
a propose
b adjust
c manifest
d ascertain

Explanation:

"Propose" means to suggest, "adjust" is to make changes, "manifest" is to show or demonstrate. "Ascertain" means to find out or determine with certainty. In the context of a speed - gun determining the vehicle's velocity, "ascertain" is the most appropriate as it implies determining precisely.

Answer:

D. ascertain