There are several approaches. The most favourable one (in my opinion) is this one:
1. Asking a question
2. Doing a research (how to answer this question)
3. Creating a hypothesis (NOT a thesis!)
4. Experimenting (to prove the hypothesis)
5. Analysing results from the experiment
6. Writing a thesis
It is because of static electricity
The atom becomes positively charged.
EXPLANATION :
When all the electrons are removed from the atom, the atom contains only protons and neutrons. The neutron is a neutral nucleon. ...
Hence, the correct answer is that atom will be positively charged.
Force=mass*acceleration. So 88kg*10 m/s^2=880 newtons
You didn't actually include the speed of sound. But it doesn't matter for this question. If the trumpeter and the listener are on the same moving sidewalk then the distance between them is not changing. The Doppler shift only happens when the distance between the source and the Observer is changing. So the Listener hears the same 290 Hertz that the trumpeter is generating.