Answer:
Students who take a PE class and who will be eating sugary snacks before PE.
Explanation:
The control variable (or control group) is an experimental element which is constant or unchanged throughout the course of the experiment.
The option "students who take PE class and who will be eating sugary snacks before PE" will remain unchanged and constant because the whole point of the experiment is to see the effects on students performance in PE after eating sugary snacks.
Hope this helps :)
Answer:
chlorination and ozonation disinfection
A. 12.5 m/s.
The average speed is defined as the relationship between the displacement made by a body and the total time it took to perform it.
The formula that will allow you to calculate the average speed is:
v = d/t, where d is the traveled distance and t the time it took to travel the distance.
We hace to convert 4 minutes to second:
(60 s/1 min)*(4 min) = 240 s
So, the average speed is:
v = 3000 m/240 s
v = 12.5 m/s
