Answer:
I only really know the "How do we use these EM waves in our lives?" part srry
Explanation:
EM waves are used to make sure you cellphone, radio, TV, and etc. have service/ connection.
The object is not accelerating
At 305 and 309 it was negative because it is going down
at 300 and 301 and 305 it was positive because its going up
at 302/303/304/306/309 she wasn't accelerating at all because it is staying the same
