Answer:
mv
Explanation:
momentum = mass * velocity
This is the Doppler effect.
1. As the sound leaves the horn the sound waves are at first close to each other and as they move outwards they become further apart. The closer the sound waves are the louder the noise.
As the car gets the closer the sound waves get closer, so the horn becomes louder.
2. As the horn moves away, the sound waves become less frequent, causing the pitch to get lower.
Collaboration in science is important because if only one scientist does an experiment, and gets a result, he/she could have messed. So this is where collaboration comes in. A few other scientists could try the experiment, and if they get the same answers, the result may be proven correct.
Hope this helped!
Answer: option B
Explanation: when a neutral atom loses an electron or gains a positive charge electron, it becomes a positive ion (positively charged) and when an neutral atom gains an electronic charge or losses a positive charge electron, it becomes a negative ion (negatively charged).