Average velocity = (displacement) / (total time)
Displacement = distance and direction between
the starting point and the end point
The car travels 90 meters north, then 40 meters south.
So it ends up 50 meters north of where it began.
Displacement = 50 meters north
Total time = (15 + 5) = 20 seconds
Average velocity = (50 meters north) / (20 seconds)
= 2.5 m/s north
Answer: A and B
Explanation: it says benefits and the other two are not benefits.
Electrons have a negative charge, so if you give away electrons, you give away negative charge, thus ending with a positive charge.
Answer:443.1 s
Explanation:
Given
Engine of a locomotive exerts a force of 
Mass of train
Final speed (v)
F=ma
so 

and acceleration is



Conserve natural resources, energy and landfill space.