Answer:
65.625 m/s
Explanation:
[tex]F=20\times 10^9 Hz[/tex]
[tex]\Delta F=F_r-F_t=4750 Hz[/tex]
c = Speed of light = 3×10⁸ m/s
Relative speed
[tex]v=\frac{\Delta F}{2F}\times c\\\Rightarrow v=\frac{4750}{2\times 20\times 10^9}\times 3\times 10^8\\\Rightarrow v=35.625\ m/s[/tex]
Relative speed = 35.625 m/s
Velocity of speeder = Velocity of police car + Relative speed
⇒Velocity of speeder = 30 + 35.625 = 65.625 m/s
∴ Velocity of speeder is 65.625 m/s
