Answer:
A control should have been included in the investigation
Explanation:
It is impossible for the student to interpret a correct conclusion about his experiment, without adding a control treatment where he can really compare the differences between the variables.
Control treatment is an element of research that receives all factors, except the variable being tested. The control serves to make comparisons with the other treatments, allowing to observe the exact difference between a system where the variable was tested and the system where it was not.
In the case of the question above, it would have been necessary for the student to have placed a cart on a ramp of normal height and without sandpaper. That way he could compare the speed between this cart and the carts on the other ramps, thus having a correct result.
Answer:
huh?? what does that mean?
The population of Georgia has increased since then. Pretty much everywhere in the world the population is always increasing.
