Answer:
The correct answer is C
Explanation:
From the question we are told that
The frequency of the radar is [tex]f = 24.15 \ GHz = 24.15 *10^{9} \ Hz[/tex]
The speed of the car is [tex]v = 50 mph = \frac{50}{2.237} = 22.35 \ m/s[/tex]
Generally the difference frequency reflected by the car and the frequency which the radar receives back is mathematically represented as
[tex]\Delta f = \frac{f * 2 * v }{ c }[/tex]
Here c is the speed of light with value [tex]c = 3.0 *10^{8} \ m/s[/tex]
=> [tex]\Delta f= \frac{2 * 24.15 *10^{9} * 22.35}{ 3.0*10^{8}}[/tex]
=> [tex]\Delta f = 4000 \ Hz[/tex]
=> [tex]\Delta f = 4.0 \ kHz[/tex]
Given that the value is positive then it a higher frequency
