# Newton’s second law of motion

Newton’s third law of motion
Vectors

Written Assignment 2
Answer all of the following questions. Answer eachquestion as completely as possible, but do not merely copy answers from your reading materials. If you citea reference in the text, explain the meaning of the citation.

(a) What are the units of mass and the units of weight for the metric system?
(b) What are the units of mass and the units of weight for the English system?

2.Explain the relationship between the mass and the weight of an object. Is the mass of an object the
same on earth and the moon? Are the weights the same on earth and the moon?

3.In your own words, explain Newton’s second law of motion and give two examples.

4.How does mass affect the rate of acceleration in free fall:
(a) In air?
(b) In a vacuum?

5.If the mass of a sliding block is tripled while a constant net force is applied, by how much does the
acceleration decrease?

6.Explain the difference between a vector and a scalar quantity. Give at least two examples of
different variables that are vector and scalar quantities.

7.Give an example of Newton’s third law of motion and explain why it is an example.

8.For each of the following interactions, identify the action and reaction forces:
(a) A hammer hits a nail.
(b) Earth’s gravity pulls down on a book.
(c) A helicopter blade pushes air downward.

9.(a) If you stand next to a wall on a frictionless skateboard and push the wall with a force of 30
Newtons, how hard does the wall push on you?