Work out the following problems. Be sure to show your work in detail. See the “Module 2 Handout” for examples of how the problems should be solved and presented.

(Problems revised September 2012)

1. State and explain Newton’s Three Laws of motion, giving examples from daily life.

2. A 1500 kg car is accelerating at a constant rate. In two seconds, its velocity goes from 10 to 30 km/hr. What is the total force acting on the car, in N?

3. An astronaut in his space suit has a total mass of 300 kg. His weight on the asteroid Ceres is 2.00 N. What is the acceleration of gravity on Erewhon?

4. A 50 kg cannon shell is subjected to a constant acceleration of 1200 g while in the cannon barrel. What force is the burning propellant exerting on the shell?

5. Four forces, represented by four vectors, are plotted in standard position on the Cartesian plane. The lengths of the vectors, in arbitrary units, represent the strength of the forces in N. The forces are being applied to an object with a mass of 1 kg, located at the origin. In what direction will the object accelerate, and how rapidly? The force vectors are A(5,5) B(-3,-2) C(-1, 6) and D(-6, 3).

Case Assignment Expectations:

Point Allocation for Grading

Problem Components

Problem

Total

Prob. #

Variables

Relationships

Computation

1

6*

6*

12

2

4

8

4

16

3

4

8

4

16

4

4

8

4

16

5

10

20

10

40

Guidelines for Full Credit:

Variables: All variables are stated, both known and unknown, in appropriate units. Variables have been converted to an appropriate metric (e.g., MKS).

All relevant equations are shown and a solution procedure is indicated.

Computations are correct, and presented in detail. The correct answers are stated, with an appropriate degree of accuracy. (Example: An answer with six-digit accuracy is not appropriate if the input data are only known to one digit.)

* Problem 1 only:

Variables : Complete and accurate statements of Newton’s Laws of Motion.

Relationships: Clear, relevant example of each Law.