The answer is definitely C.) their molecules move at the same average speed
Is there a question? Because All your doing t explaining a british philosopher to us..
Answer:
Average velocity

Average speed,

Explanation:
(a)Average velocity
We have to find the average velocity. We know that velocity is defined as the rate of change of displacement with respect to time.
To find the average velocity we have to find the total displacement.
since displacement along east direction is 50m
and displacement along west=40m
so total displacement,

total time,

therefore, average velocity

(b)Average Speed:
Average speed is defined as the ratio of total distance to the total time
it means
Average speed= total distance/total time
here total distance,

and total time,

therefore,
Average speed,

Answer:
Circulatory System
Explanation:
The respiratory system works with the circulatory system to provide tis oxygen and to remove the waste products of metabolism. It also helps to regulate PH of the blood. Respiration is the sequence of events that result in the exchange of oxygen and carbon dioxide between the atmosphere and the body cells.
Find the amount of work that the spring does. This can be found using the equation 1/2kx^2. Then, you must set that equal to the amount of kinetic energy the car has. This is possible thanks to the work-energy theorem.
1/2kx^2 = 1/2mv^2
Solve to find velocity. Remember, the spring is displaced .15 m, not 15!
To find the acceleration, use F = ma. The force being applied to the car is kx, and you know the mass. You do the math.
For problem C I don't know, haven't done that yet in my class. Sorry!