1. Multiple Choice. Choose the best answer from the selection. Write the letter of your choice befor the item No. 1. One kilometer is approximately A. $\mathbf{2}$ miles B. $x$ mile C. $1 / 10$ mile D. Xmile 2. If the speed of the light is approximately measured as $3.00 \times 10^{4} \mathrm{~m} / \mathrm{s}$, the distance it travels in 1.00 ns is approximately A. $3.00 \times 10^{-2} \mathrm{~m}$ C. $3.00 \times 10^{1} \mathrm{~m}$ B. $3.00 \times 10^{-1} \mathrm{~m}$ D. $3.00 \times 10^{2} \mathrm{~m}$ 3. In terms of the original diameter $d$, what new diameter will result in a new spherical volume that is afactor of eight times the original volume? A. $8 d$ C. $d x \sqrt[3]{2}$ B. $2 d$ D. $d / 8$ 4. How many significant figures should be written in the sum of $4.56 \mathrm{~g}+9.032 \mathrm{~g}+580.0078 \mathrm{~g}+$ $540.439 \mathrm{~g}$ ? A. 3 C. 6 B. 4 D. 7 5. How many significant figures should be written in the product of $0.00784 \mathrm{~m} \times 9.45020 \mathrm{~m}$ ? A. 3 C. 6 B. 4 D. 7 11. Problem Solving. Solve the following problems with complete solutions. 1. Estimate the number of molecules in $1.00 \mathrm{~m}^{3}$ of air by assuming that it has a density of $1.21 \mathrm{~kg} / \mathrm{m}^{3}$ and that is entirely composed of nitrogen molecules. 2. The mean radius of the earth is $6370 \mathrm{~km}$. (a) What is the area of the earth's surface in square meters? square centimeters? square feet? 3. A block of wood occupies a space $8.00 \mathrm{ft}$ long. $4.00 \mathrm{ft}$ wide, and $4.00 \mathrm{ft}$ high. What is the volume of the cord in cubic meters? 4. The density of water at $4.00^{\circ} \mathrm{C}$ is $1.00 \mathrm{~g} / \mathrm{cm}^{\prime}$. Convert the density to (a) $\mathrm{kg} / \mathrm{m}^{\prime}$ and $(\mathrm{b}) \mathrm{lb} / \mathrm{ft}^{\prime}$.

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