Question

If the scientist tested that question by racing cars with different engine power and measuring their maximum speed, what CONTROLLED VARIABLES should they use? (Check 2 answers)

A) Power
B) Speed
C) Size of the car
D) Type of gasoline used

Answer 1

The scientist should use the size of the car and the type of gasoline used as controlled variables in the experiment.

Step-by-step explanation:

The controlled variables that the scientist should use in the experiment are:

1. Size of the car: The size of the car should be kept constant in order to isolate the effect of engine power on the maximum speed. If different sizes of cars are used, it may lead to variations in the aerodynamic drag and tire friction, which can affect the results.
2. Type of gasoline used: The type of gasoline used should be kept constant to make sure that the fuel composition and energy content remain the same. Different types of gasoline can have different energy densities, which can affect the performance of the engine.