C. A paramecium is a single-celled organism that lives in ponds. It travels at a rate of 2,000 micrometers per second. What is the speed of the paramecium in meters per hour?

7.2 meters per hour

Explanation:

It is given that,

The speed of a paramecium is 2,000 micrometers per second.

We need to find the speed of the paramecium in meters per hour.

We know that,

and

1 hour = 3600 seconds

Hence, the speed of the paramecium is 7.2 meters per hour.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.