A Radar Unit Operates at a Wavelength of 4 $3.0 \times 10 ^ { 8 }$

Multiple Choice

A radar unit operates at a wavelength of 4.2 cm. Radar waves travel at the speed of light, which is $3.0 \times 10 ^ { 8 }$ . What is the frequency of the radar waves?

A) 7.1 $\times 10 ^ { 6 }$ Hz
B) 7.1 $\times 10 ^ { 9 }$ Hz
C) 6.7 $\times 10 ^ { 9 }$ MHz
D) 7.1 $\times 10 ^ { 9 }$ MHz
E) 6.7 $\times 10 ^ { 9 }$ Hz