Answer:

Explanation:
The speed of the sound wave is:


The frequency is:



Answer:
I don't see any actions, but I found these examples online
Not taking unnecessary risks.
Always look out for hazards.
Always use Personal Protective Equipment (PPE)
If you must smoke, do so only in designated areas.
Keep your work area clean and tidy.
Enter and leave the workplace using proper routes.
Be Aware
Maintain Correct Posture
Take Breaks Regularly
Use Equipment Properly
Locate Emergency Exits
Report Safety Concerns
"Exploded", because more people wanted to get work in factories, etc.. and they thought it was a better to work in industries then farming.
conditions were poor in most cases, and that led to the creation of unions in most cases.
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