Physics for Poets                                                         June 13, 2002                                                                        Mail # 
 

Instructions: This test has the same format as before. Part A consists of short answer questions where you are to pick the best work, phrase, or choice of answer which best answers or, in some cases, defines the statement. Part B consist of longer answer questions. Make your answers clear and concise. For Part A please use the rules for precision or significant figures if data has been measured (indicated by the underline of the precision digit.) If you need more room turn over the test paper and continue on the back but please indicate on front. For problems it is the procedure that will be checked, not only the answer, so please try to make it clear. So for this, the 2nd poets' test of the term, Good Luck!
 

Declaration: I elect to do a (term paper, lab project). Please circle. 
 

1. (10) REVIEW QUESTION PLUS: Choose from the physical quantities which we have discussed - length, area, volume, time, mass, force, velocity (or speed), acceleration, period - to identify the following quantities taken from problems.
 

a) 25.2 m                                                                       f) 3.74 m³                                              l) 23.4 m²
 

b) 21.3 square ft                                                                     g) 1.43 kg                                      m) 23.2 g
 

c) 7.48 m/sec                                                          h) l.85 m/sec²                                          n) 78.3 N
 

d) 4.92 sec                                                                       I) 3.54 lb sec²/ft                             o) 33.2 H
 

e) 5 sec/cycle                                                                    j) 5.3 in/sec                                               p) 7.1 kg m/sec²

2. (4) For the following two length measurements indicate the precision and number of significant figures for each, add them, and multiply them using the rules strictly. (Include units for parts "c" and "d.")

                                                                                          Precision                                          No. of significant figures
 

a) 43.24 cm 
 

b) 210.4 cm 
 

c) sum of a) + b) equals 
 

d) product of a) times b) equals 
 

3. (2) A pendulum was observed to take 65.0 sec to make 80.8 complete swings (or cycles). It's period is ? 
 

4. (1 ½ ) A person weighing 250 lb here on earth goes to planet X having a radius three times that of the earth and a mass six times as large. The person will weigh ? on the surface of that planet.

5. (1 ½ ) A person weighing 120 lb here on earth goes to planet Y having a radius one-half that of the earth and a mass 4 times greater than the earth. The person will weigh ? on the surface of that planet.
 

6. (1) The amazing generalization that was made by Newton as he was studying the force holding the moon in orbit and the force that caused the apple to drop from the tree was ? .
 

7. (2) A person 4000 mi from the center of the earth weighs 120 lb. How much will she weigh at a distance of 12000 mi from the center?
 

8. (3) For question 7, does the mass of the woman change at the distance of 12000 mi from the center? What is the acceleration due to gravity at this height? (Note: It is not 32 ft/s/s.)

Physics 1130 - Test 2 - page 2
 

9. (1 ½ ) A lunar month is about 28 days. If the moon were closer to the earth than what it presently is, the lunar month would be (a) less than 28 days, (b) unchanged, (c) greater than 28 days. (Choose one.)
 

10. (1) When a comet is farther from the sun, its speed (a) is faster (b) is slower or (c) does not change from what it is when it is closer from the sun. (Choose one.)
 

11. (1 ½ ) An object is being twirled at the end of a string in a circular motion at constant speed. The force exerted by the string on the object directed inward toward the center of the circle is called the ? force.
 

12. (1) Does the force described in question 11 cause the object to speed up or slow down? (Yes, No).
 

13. (2) Does an acceleration exist for the motion of question 11? (Yes, No). Explain your answer: 

.

14. (1 ½ ) Describe the "reaction" force to the force that is described in question 11? 

15. (3) Three ways of reducing friction are ? , ? , and ? .

16. (1) The force exerted by the earth on our body is called ? .

17. (2) For a projectile, its horizontal motion is (a) accelerated, (b) at constant speed, (c) non existent. (Neglect air friction.)

18. (2 ) For a projectile, its vertical motion is (a) accelerated, (b) at constant speed, (c) non existent. (Neglect air friction.)

19. (2) Explain why the following statement is technically incorrect: "As a car rounds a corner, there is a force which pushes the person to the side". 

20. (1 ½ ) The mass of a 147 N object is ? 

21. (1 ½ ) The mass of a 22 kg object is ? .

21. (1 ½ ) The mass of a 192 lb object is ? 

22. (1) The name of a person who first determined an elaborate model that was based on an earth-centered Universe with planets traveling around circles whose centers were in circlular orbits about the earth. This model was so powerful (albeit complicated) that it could predict solar eclipses!

23. (1) A less complicated model placed the sun at the center of our solar system and maintained equal, if not better, prediction capabilities as the model of question #22 was devised by ? .

24. (1) A Danish astronomer that spent his whole life taking remarkably accurate data of the planets that later was used by Kepler was ? .

25. (1) A circular hoop is turned at a slight angle relative to an observer. The observer sees a geometric curve called ? .
 

26. (1) The horizontal distance traveled by a projectile is called ? .
 

Physics 1130 - Test 2 - page 3
 

B. Longer Answer Questions:

1. (4) A net force of 50 N accelerates an object at 2 m/sec². 

(a) What is the mass of the object? 
 

(b) What is the weight of the object?
 
 
 

2. (a)(3) (Parts b and c are REVIEW.) A woman exerts a force of 260 N to a full grocery cart whose mass is 100 kg. (This is one strong woman!) There is a frictional force of 60 N acting in the opposite direction. What is the acceleration of the cart? (Hint: First find the NetForce.)
 

(b)(2) How fast will the cart be moving after 5 sec if it starts from rest?
 
 
 
 

(c)(2) How far will the cart move after 5 sec again starting from rest?
 
 
 
 

3. (4) Distinguish between true weightlessness and apparent weightlessness.
 
 

4. (4) State all three of Kepler's Laws and use diagrams where helpful.
 
 
 
 
 
 
 
 

Physics 1130 - Test 2 - page 4
 

5. (5) (a) Explain what is meant by a "direct" proportion. (b) How can one prove clearly and convincingly that two physical quantities are indeed directly proportional? (c) What is a "constant of proportionality?"
 
 

6. (4) (a) Explain what is meant by the term "terminal velocity." (b) Upon what other physical quantities does terminal velocity depend?
 
 
 
 
 
 
 
 
 
 

7. A plane is flying horizontally at 4000 ft above the surface of the earth and drops a care package. Neglect air friction and assume a flat earth.
 

(a) (3) Explain the horizontal and then the vertical motion of the care package relative to the plane.
 
 
 
 
 

(b) (2 bonus points!) Calculate the time that it takes for the care package to strike the ground.
 
 
 
 
 
 
 

8. (4) State Newton's Third Law and make up two specific examples of its use. Include diagrams and show and explain all forces.
 
 
 
 
 
 
 

Physics 1130 - Test 2 - page 5

9. Define or briefly describe the following terms:

(2) centrifugal force
 
 
 
 
 
 

(2) the projection angle for maximum range (a) without friction and (b) with friction included
 
 
 
 
 
 
 
 
 

(2) centrifuge
 
 
 
 
 
 

(2) instrumental errors (when writing up a laboratory)
 
 
 
 
 
 

(2) inherent errors (when writing up a laboratory)
 
 
 
 
 
 
 

(2) Simulated gravity