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Answer: Doppler effect
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Explanation:
A radar gun (also known as a Doppler radar) uses the Doppler effect when measuring "return echoes" after having sent a microwave signal (a type of electromagnetic radiation).
In this context the Doppler effect consists of the change in a wave perceived frequency when the emitter of the waves, and the observer move relative to each other.
In the case of radars, a microwave signal is sent to a target (the tennis or baseball in this case) and then is reflected after "hitting" the target, so that the radar system measures this difference between the sent signal and the reflected signal.
The answer to the question is true
Answer:
The speed of the vehicle changes in each second is, v = 0.00111 Km/h
Explanation:
Given,
The acceleration of the vehicle, a = 4 Km/h²
Converting it into m/s,
a = 0.0003086 m/s²
In each second the vehicle covers 0.0003086 m
The speed of the vehicle in each second is given by 0.0003086 m/s
Converting it into Km/h
v = 0.00111 Km/h
Therefore, the speed of the vehicle changes in each second is, v = 0.00111 Km/h