Major Quiz 1 Please Show Your Work

MAJOR QUIZ 1 – PLEASE SHOW YOUR WORK.

DON’T FORGET SIGNIFICANT FIGURES AND UNITS.

1. Which area of physics studies motion and its causes?

Classical mechanics: describes the motion of the objects that are large compared with the dimensions of atoms (10-10 m) moving at speeds that are low compared to the speed of light (3108 m/s).

2. What does relativity (theory) deal with?

Relativity describes particles moving at any speed, even those whose speed approaches the speed of light;

3. The number of heartbeats of a person at rest in one hour, to the nearest order of magnitude is

A. 101.

B. 102.

C. 103.

D. 105.

4. Which is the best measurement of this object?

2 cm
1.9 cm
1.94 cm
1.942 cm

5. Why do physicists use models?

a. / to explain the complex features of simple phenomena
b. / to describe all aspects of a phenomenon
c. / to explain the basic features of complex phenomena
d. / to describe all of reality

6. State the number of significant digits in each measurement.

a. 2804 m (4) b. 2.84 m (3) c. 0.0029 m (2) d. 4.6 x 105 m(2) e. 4.06 x 10-5 m (3)

7. Complete the following statement: Today, the standard unit of time is defined in terms of

a. / the electromagnetic waves emitted by cesium atoms.
b. / the motion of the moon around the earth.
c. / the motion of a precision pendulum.
d. / the average solar day.
e. / the speed of light.

8. Basic SI units used in mechanics are __meter (m), kilogram (kg) and second (s)__

9. Give some examples of derived SI units:

it is combination of basic units:

volume – m3 , area – m2, density – kg/m3, speed - m/s, acceleration - m/s2, force – kg.m/s2, …..

10. An ammeter has a zero offset error. This fault will affect

A. neither the precision nor the accuracy of the readings.

B. only the precision of the readings.

C. only the accuracy of the readings.

D. both the precision and the accuracy of the readings.

Precision is the degree of exactness or refinement of a measurement (results from limitations of measuring device used).

Accuracy is the extent to which a reported measurement approaches the true value of the quantity measured – how close is the measurement to the reality.

11. How many micrograms make 1 kg?

1kg = 103 g 1 g = 106 g 1kg = 103 g = 103x106 g = 109 g

12. Which one of the following answers would give the correct number of significant figures when the following masses are added together: 3.6 kg, 113 kg, and 4.19 kg?

a. / 121 kg / c. / 120.79 kg / e. / 120.8 x 103 kg
b. / 120.8 kg / d. / 1.20 x 102 kg

13. There is no SI base unit for "area" because:

we don’t need it. Unit for area is combination of two units mxm=m2.

14. Which one of the following choices is equivalent to 2.0 m2?

a. / 2.0 x 104 cm2 / b. / 2.0 x 104 cm2 / c. / 2.0 x 10-2 cm2 / d. / 2.0 x 102 cm2 / e. / 2.0 x 103 cm2

1 m = 102 cm 2.0 m2 = 2.0 x (102 cm )2

15. If some measurements agree closely with each other but differ widely from the actual value, these measurements are

a. / neither precise nor accurate. / c. / acceptable as a new standard of accuracy.
b. / accurate but not precise. / d. / precise but not accurate.

16. You are asked to find the area of a room that is 4.56 m long and 5.668 m wide. How many significant figures should you show in your answer?

3 SF (3SF x 4SF = 3SF)

17. The Newton’s second law is . SI unit for acceleration is m/s2.

Find unit for force!

(Force) = (mass).(acceleration) (Force) = kg.m/s2

18. The ratio is

19. Which of the following is closest to your height?

a. / 0.02 m / b. / 0.2 m / c. / 2 m / d. / 200 m / e. / 2000 m

20. Which of the following is closest to your mass?

a. / 0.06 kg / b. / 0.6 kg / c. / 6 kg / d. / 60 kg / e. / 600 kg

21. 1 mi is equivalent to 1609 m so 65 mi/h is: 2SF

22. Determine the following to the correct number of significant figures:

A. (3.74 - 1.3) x 2.12 x 17.65

B. (2.9 + 3.2 + 7.1)  0.134

A. 91

B. 99

23. Which SI prefix means one million?

a. / kilo- / b. / mega- M = 106 = 1 000 000 / c. / giga- / d. / milli-

24. A cubic box with an edge of exactly 1 cm has a volume of:

a. / 10–9 m3 / b. / 10–6 m3 / c. / 10–3 m3 / d. / 103 m3 / e. / 106 m3

1 cm = 10-2 m V = 1 cm3 = (10-2 m)3 = 10–6 m3

25. Convert each of the following time measurements to its equivalent in seconds.

a. 58 ns = 58x10-9 s = 5.8x10-8 s

b. 0.046 Gs = 0.046 x109 s = 4.6x107 s

26. The surface of a lake has an area of 15.5 km2. What is the area of the lake in m2?

a. / 1.55  104 m2 / b. / 1.55  105 m2 / c. / 1.55  106 m2 / d. / 1.55  107 m2 / e. / 1.55  108 m2

1 km = 103 m 15.5 km2 = 15.5 x(103 m)2 = 15.5 x 106 m2 = 1.55  107 m2

27. 645.006 m + 2.0077 m + 8.0084 m = 655.022 m the smallest number of decimal places

28. Express the following quantities in scientific notation.

a. 302 000 000 m = 3.02x108 m

b. 0.000 000 45 kg = 45x10-7 kg

29. Find the value of each of the following quantities.

30. a. (6.2 x 1018 m)(4.7 x 10–10 m) = 29x108 m2 = 2.9x109 m

31. A 2.5-m ladder leans against a wall and makes an angle with the wall of 32° as shown in the figure. What is the height h above the floor where the ladder makes contact with the wall?

a. / 2.1 m / b. / 1.3 m / c. / 2.4 m / d. / 1.6 m / e. / 1.9 m

h= (2.5m) x cos 320 = 2.1 m

***Not on the quiz . The frequency f of an oscillating system is given by

where g and π are constants.

The frequency f is measured for different values of l and a graph is plotted.

Which one of the following will produce a straight-line graph?

y – axis x - axis

√f √l
√f l
f 2 1/l
f 2 √l

1. Which area of physics studies heat and temperature?

Thermodynamics deals with heat, temperature, and the behavior of large numbers of particles;

2. What is the difference between mechanics and quantum mechanics?

Quantum mechanics is a theory dealing with the behavior of submicroscopic particles; Mechanics describes the motion of the objects that are large compared with the dimensions of atoms (10-10 m) moving at speeds that are low compared to the speed of light (3108 m/s).

3. The physical quantities can be __basic__ and __derived_

4. According to the scientific method, how should conclusions be stated?

a. / so that no one can refute the conclusion
b. / so that it works with only one set of data
c. / so that it is completely correct, with no mistakes
d. / in a form that can be evaluated by others

5. Which statement about models is NOT correct?

a. / Models describe only part of reality.
b. / Models help build hypotheses.
c. / Models help guide experimental design.
d. / Models manipulate a single variable or factor in an experiment.

6. The standard of length is based on:

a. / the distance from the north pole to the equator along a meridian passing through Paris
b. / wavelength of light emitted by Hg198
c. / wavelength of light emitted by Kr86
d. / a precision meter stick in Paris
e. / the speed of light

7. It is estimated that the sun will exhaust all of its energy in about ten billion years. By that time, it will have radiated about 1.2 x1044 J (joules) of energy. Express this amount of energy in nanojoules.

E = 1.2 x1044 J (joules) = 1.2 x1053 nJ

8. Convert each of the following time measurements to its equivalent in seconds.

a. 0.046 Gs = 0.046x109 s = 46x106 s

b. 9270 ms = 9270x10-3 s = 9.27 s

c. 12.3 ks = c. 12.3 ks = 12.3 x 103 s

9. Express the following quantities in scientific notation.

a. 0.000 360 0 kg= 3.6 x 10-4 kg

b. 0.004 kg = 4x10-3 kg

10. Basic SI units used in mechanics are: meter (m), kilogram (kg) and second (s)

11. Give some examples of derived SI units:

it is combination of basic units:

volume – m3 , area – m2, density – kg/m3, speed - m/s, acceleration - m/s2, force – kg.m/s2, …..

12. Find the value of each of the following quantities.

13. Multiply or divide as indicated:

a. (8.1 x 10–4 km)(1.6 x 10–3 km) = 13x10-7 km2

14. In the SI system, the prefix ___micro (___ means one millionth.

15. A pole is held vertically by attaching wires at a height of 13.4 m above the ground. The other end of each wire is anchored in the ground at a distance of 9.54 m from the base of the pole. The pole makes a right angle with the ground. What is the length of each wire?

a. / 14.1 m / b. / 19.7 m / c. / 11.5 m / d. / 16.4 m / e. / 22.8 m

16. A sphere with a radius of 1.7 cm has a surface area of:

a. / 2.1  10–5 m2 / b. / 9.1  10–4 m2 / c. / 3.6  10–3 m2 / d. / 0.11 m2 / e. / 36 m2

17. The ratio

18. Convert each of the following mass measurements to its equivalent in kilograms.

a. 7.23 g = 7.23x10-3 kg

b. 478 mg = 0.478 g = 0.478x10-3 kg

19. There is no SI base unit for "volume" because:

we don’t need it. Unit for volume is combination of three units mxmxm=m3.

20. The for d is . t is time; dimension for v is and SI unit is m/s . Find both dimension and unit for x!

dimension: [x] = [v].[t]2 [x] = .[T]2 = [L][T]

unit:: (x) = (v).(t)2 (x) = m.s

21. Express the following quantities in scientific notation.

a. 5800 m = 5.8x103 m

b. 450 000 m = 4.5x105 m

22. These values were obtained as the mass of a bar of metal: 8.83 g; 8.84 g; 8.82 g. The known mass is 10.68 g. The values are

a. / accurate. / c. / both accurate and precise.
b. / precise. / d. / neither accurate nor precise.

23. The surface of a lake has an area of 15.5 km2. What is the area of the lake in m2?

a. / 1.55  104 m2 / b. / 1.55  105 m2 / c. / 1.55  106 m2 / d. / 1.55  107 m2 / e. / 1.55  108 m2

24. Which is the proper measurement of this object?

3.8 cm
3.82 cm
3.8 mm
3.82 mm

25. A theory is

a. / an educated guess that has yet to be proven by experiment.
b. / close agreement by competent observers of observations of the same phenomena.
c. / a science story about atoms and molecules.
d. / a guess that has been tested over and over again and always found to be true.
e. / a synthesis of a large collection of information including well-tested guesses.

26. Which of the following is closest to your height?

a. / 0.02 m / b. / 0.2 m / c. / 2 m / d. / 200 m / e. / 2000 m

27. Which of the following is closest to your mass?

a. / 0.06 kg / b. / 0.6 kg / c. / 6 kg / d. / 60 kg / e. / 600 kg

28. 1 mi is equivalent to 1609 m so 35 mi/h is:

29. Which one of the following choices is equivalent to 2.0 m2?

a. / 2.0 x 104 cm2 / b. / 2.0 x 104 cm2 / c. / 2.0 x 102 cm2 / d. / 2.0 x 102 cm2 / e. / 2.0 x 103 cm2

30. You are asked to find the volume of a cube that is 2.5 cm high, 2.65 cm wide, and 3.456 cm long. How many significant figures should you show in your answer?

2 SF

31. Which one of the following answers would give the correct number of significant figures when the following masses are added together: 3.6 kg, 113 kg, and 4.19 kg?

a. / 121 kg / c. / 120.79 kg / e. / 120.8  103 kg
b. / 120.8 kg / d. / 1.20 x 102 kg