Vocabulary tasks:

8. Answer the following questions to the text.

1. Where is Newton's analysis of motion summarized?

Newton's analysis of motion is summarized in his famous "three laws of motion"

2. What does the Newton’s first law state?

The first Newton’s law stat was: Every body continues in its state of rest or of uniform speed in a straight line unless acted on by a nonzero net force.

3. What can we call inertia?

The tendency of a body to maintain its state of rest or of uniform motion in a straight line is called inertia.

4. Does Newton's first law hold in every reference frame?

No, Newton's first law does not hold in every reference frame.

5. What is noninertial reference frame?

The noninertial reference frames is reference frames where the law of inertia does not hold, such as the accelerating reference frame discussed above.

9. Are the following statements about the text true or false?

1. Newton's first law of motion is far from to Galileo's conclusions. - False

2. Newton's first law is often called the law of relativity. - True

3. Reference frames in which Newton's first law does hold are called velocity reference frames. - True

4. The accelerating reference frame are called inertial reference frame. - False

5. Every body continues in its state of rest or of uniform speed in a straight line unless acted on by a nonzero net force. - True

10. Match the first part of the sentence (1 –6) with the second part (a-f).

1. C) Newton's analysis of motion is summarized in his famous "three laws of motion".

2. F) The Principia is a great work

3. A) Newton's first law does not hold in every reference frame.

4. E) We can assume that reference frames fixed on Earth's rotation.

5. D) How can we be sure a reference frame is inertial or not?

6. B) The law of inertia is valid in reference frames.

a  in every reference frame.

b in reference frames.

c  in his famous "three laws of motion".

d is inertial or not?

e  on Earth's rotation.

f a great work.

11. Complete the sentences with words from the box.

acceleration - motion -  law - velocity - concepts - inertia

1. They introduced partially defined concepts .

2. Newton's first law is often called the law of inertia.

3. The more mass a body has, the harder it is to change its state of inertia .

4. We can say that mass is a measure of the motion of a body.

5. Newton perceived that the acceleration will change.

6. The velocity depends on the mass of the object as well.