Answer
a) The car acts as a moving observer. Due to its oncoming motion, the car strikes the electromagnetic waves at a higher rate than if it were at rest. Thus, the reflected waves will have a higher frequency than the waves had when emitted by the radar gun.
b) The frequency is higher and the wavelength is shorter. The reflected wave speed is the same as the original wave speed since both are electromagnetic waves in the same medium, air, which is close to a vacuum, so that speed would be c.
Work Step by Step
a) The car acts as a moving observer. Due to its oncoming motion, the car strikes the electromagnetic waves at a higher rate than if it were at rest. Thus, the reflected waves will have a higher frequency than the waves had when emitted by the radar gun.
b) The frequency is higher and the wavelength is shorter. The reflected wave speed is the same as the original wave speed since both are electromagnetic waves in the same medium, air, which is close to a vacuum, so that speed would be c.
