The length and width of a standard sheet of paper is measured, and then the area is found by calculation to be 91.50 in.2 . The number of significant figures in the width measurement must be at least
a. 1.
b. 2.
c. 3.
d. 4.
e. 5.
[Ques. 2] Calculate (0.83 + 0.049)(4.4 103), keeping only significant figures.
a. 3 900
b. 3 868
c. 3 886
d. 3 644
e. 4 000
[Ques. 3] Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 15.0 5.6 2.33?
a. 200
b. 195.720
c. 195.72
d. 195.7
e. 196
[Ques. 4] Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 15.9 + 14 + 77.68 + 6.898?
a. 114.4780
b. 114.478
c. 114.48
d. 114.5
e. 114
[Ques. 5] The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 30.0 cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 1.0 105 m. Find the total surface area of these N spherical droplets.
a. 3.0E+4 cm2
b. 1.2E+5 cm2
c. 1.8E+5 cm2
d. 9.0E+4 cm2
e. 1.1E+5 cm2
[Ques. 6] Modern electroplaters can cover a surface area of 75.0 m2 with one troy ounce of gold (volume = 1.611 cm3). What is the thickness of the electroplated gold?
a. 2.15E8 m
b. 1.07E8 m
c. 1.43E8 m
d. 4.30E8 m
e. None of the above
[Ques. 7] Volume can be measured in units of m3 . Which of the following unit combinations also result in volume?
a. ft2/m b. cmft
c. cm2in. d. m2cmft
[Ques. 8] Suppose an equation relating position, x, to time, t, is given by x = bt3 + ct4, where b and c are constants. The dimensions of b and c are respectively:
a. T3, T4.
b. 1/T3, 1/T4.
c. L/T3, L/T4.
d. L2/T3, L2/T4.
[Ques. 9] When SI units are plugged into an equation, it is found that the units balance. Which of the following can we expect to be true for this equation?
a. The equation will be dimensionally correct.
b. The equation will be dimensionally correct except sometimes in cases when the right-hand side of the equation has more than one term.
c. The equation will not be dimensionally correct.
d. All constants of proportionality will be correct.
[Ques. 10] Areas always have dimensions ____ while volumes always have dimensions ____.
a. m2, m3
b. L2, L3
c. Both a and b are correct.
d. No answer is correct because of the always.
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