In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.

Q: Question: If Mona is bouncing radar waves off a test car when training to be a policewoman and she notices the frequency of the waves returning to her radar gun is lower then it was before, what is happening to the car she is pointing the gun at?
Answer: decreasing in speed

A: A: As the car approaches the radar gun, the reflected microwaves get bunched up in front of the car. Therefore, the waves the receiver detects have a higher frequency than they would if they were being reflected from a stationary object. The faster the car is moving, the greater the increase in the frequency of the waves.
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Q: Question: When we lower the temperature of water it becomes
Answer: more dense

A: When a volume of water is cooled, the molecules move less vigorously, so same number of molecules takes up less space and the water is denser.
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Q: Question: Timmy turned down his speakers to soft volume, meaning the sound waves had _____ energy.
Answer: lower

A:
Amplified sound waves have more energy, which increases the intensity and loudness of the sounds, so they are easier to hear.
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