Chapter 1.2 Review

1. How can numerous measurements be taken in science when there are only seven fundamental units of measure?

The fundamental units can be combined to form derived units.

2. Why is the metric system called the MKS system?

Because the most commonly used units are meter, kilogram, and second.

3. List the basic measurements in physics and tell how they are measured.

meter – the distance light travels in a tiny fraction of a second.kilogram – the mass of the standard kilogram (the only measure that is still a natural object)second – a certain number of vibrations of a cesium-133 atom

4. How is the metric system based on liquid water?

1 ml = 1 cm3 = 1 gram of liquid water

1 calorie raises the temperature of 1 g of liquid water 1 degree celsius

5. What is the difference in accuracy and precision?

Accuracy is how close a measurement is to the “right “ answer. Precision is how repeatable the measurement is.

6. Why is relative error a more meaningful measurement than absolute error?

Because it is a percentage of the correct value.

7. If measurements aren’t precise, what does that tell you about the measurements?

There is some flaw in the way the experiment is being done.

8. Give an example of a situation where numbers are not significant.

If you told someone that 500,000 people live in Denton county you don’t man exactly 500,000. Most of those zeros are not significant.

9. What is the most important step in problem solving and why?

“Check your answer for reasonableness.” Because you don’t want to look foolish. More importantly, it will cause you to look back and correct your answer.