QUIZ 1(ANSWERS)-Problems below correspond to online assignment

CH. 1 - DISCUSSION QUESTIONS 1,  4, 7

CH  1 - EXERCISES/PROBLEMS: 10; 11; 15; 13; 56; 26; 27.

CH. 4 - DISCUSSION QUESTIONS 1, 2, 5, 6

CH. 4 - EXERCISES/PROBLEMS: 1, 3, 4, 6

HINTS:

CH. 1 - DISC QUESTIONS: 1, 4, 7

1.  Remember, for every  scientific hypothesis there exists an experiment such that  a "negative" result disproves it. If you don't find what you're looking for-a "negative" result-you'd say with confidence the hypothesis  is wrong.  "There exists Extra-terrestrial humanoid life in the Universe"  is not a scientific hypothesis.  If you don't find Extra-terrestrials, it doesn't mean they don't exist-your range  of investigation could never be sufficiently large. But as ridiculous as it sounds, " The Moon is made of cheese" is  a scientific claim  assuming there exists  means to examine the Moon in sufficient detail. No such test exists for Extra-terrestrials.

THOUGHT PROBLEM: WHAT IS THE TANGENT FOR FOLLOWING RUN AND RISE VALUES?  Compute rise/run, rise = 120 m, run = 1 kilometer.

4. added mass = (rise/run)*time. Think about why the mass increases.

7.  For 3.14159...., , the number of radians in a half-circle, what are the two lengths?  Think about #2  and  other  dimensionless ratios.

CH  1 - EXS/PROBS: 10; 11; 15; 13; 56; 26; 27. NOTE:  FOR #10, SEE SEC 1.4 EXAMPLES.

11.mass = density* sphere volume  w/  required conversions.

15. Find x1 = number of seconds in 365.24 d with  5 sig. figs. Compute |x1 - x2|*100%/x1, where x2 = pi*107   and  pi = 3.14159..... and % is short hand for division.  Use sig. fig.  rules for subtraction/addition, multiplication and  division. Visit: http://library.thinkquest.org/10796/ch1/ch1.htm  .

13;;;; 890 km = 890,000 m with 2 sig. figs,  precise to the 10,000's place (in m) or 10's place (in km),  a large number with low precision.  Now 10 m is precise to the 10's place. You'd write 890 km = 890,000 m  and 10 m   = 0.01 km. Thus,  890 km + 0.01 km = 890.01 km = 890 km. For the given precisions, adding 10 m has  no effect after rounding. PE  = |x1 - x2|/x1*100%, where x1 = 890.01 km and x2 = 890 km and % is short hand for division.  The difference is  zero after rounding.  See http://library.thinkquest.org/10796/ch1/ch1.htm .

52;;;.   Period = 1/frequency; # cycles = frequency*time.

26;;;.   Done in class lecture notes in some form..

27;;;. See section 1.8. There are three displacements. With respect to page, the first  is vertical, the second horizontal  and the third lies 45 degrees above horizontal with magnitude 3.1 km.  Find Dx and Dx,  x and y components of total displacement  vector-D.  Clearly Dx = 4.0 + the x-component of third displacement and Dy = 2.6 + y-component of third displacement.  Find  vector-D magnitude using the Pythagorean Th. Tan theta = Dx|/|Dy| where theta is related angle.  In what quadrant does vector -D point?