Correlation between speed of an automobile and distance travelled after applying brakes

Correlation refers to the statistical relationship between two variables. In this case, the two variables are the speed of an automobile and the distance travelled by it after applying the brakes.

Positive correlation: If there is a positive correlation between two variables, it means that they are positively related. This means that as one variable increases, the other variable also increases. Similarly, if one variable decreases, the other variable also decreases.

Negative correlation: If there is a negative correlation between two variables, it means that they are negatively related. This means that as one variable increases, the other variable decreases. Similarly, if one variable decreases, the other variable increases.

Zero correlation: If there is zero correlation between two variables, it means that there is no relationship between the two variables.

Applying the concept to the given question

When an automobile applies brakes, the distance travelled by it before coming to a complete stop depends on various factors such as the initial speed of the automobile, the condition of the brakes, road conditions, etc. However, in general, we can say that:

- As the speed of an automobile increases, the distance travelled by it before coming to a complete stop also increases.
- As the speed of an automobile decreases, the distance travelled by it before coming to a complete stop decreases.

Since the two variables (speed and distance travelled after applying brakes) are positively related, the correlation between them is positive. Therefore, the correct answer is option C - positive.

Positive (c)