(a) How many significant figures are in the numbers 99 and 100? (b) If the uncertainty in each number is 1, what is the percent uncertainty in each? (c) Which is a more meaningful way to express the accuracy of these two numbers, significant figures or percent uncertainties?

(a) If your speedometer has an uncertainty of 2.0 km/h at a speed of 90 km/h, what is the percent uncertainty? (b) If it has the same percent uncertainty when it reads 60 km/h, what is the range of speeds you could be going?

The Hoover Dam Bridge connecting Arizona and Nevada opened in October 2010 ( Fig. 1.18). It is the highest and longest arched concrete bridge in the Western Hemisphere, rising 890 ft above the Colorado River and extending 1900 ft in length. What are these dimensions in meters? Figure 1.18 High and Wide An aerial view of the new four-lane Hoover Dam Bridge between Arizona and Nevada with the Colorado River beneath (as seen from behind the dam). See Exercise 16.

A floating-point operation is a single arithmetic operation such as addition, subtraction, multiplication, division. (a) Estimate the maximum number of floating- point operations a human being could possibly perform in a lifetime. (b) How long would it take a supercomputer to perform that many floating-point operations?

If the radius of a CD-ROM is 6 cm, what is the average area taken up by each bit if the total number of bits stored is 6 billion (6 x 109) bits?

If you used only a keyboard to enter data, how many years would it take to fill up the hard drive in your computer that can store 95gigabytes95gigabytes (95×109bytes95×109bytes) of data? Assume "normal" eight-hour working days, and that one byte is required to store one keyboard character, and that you can type 180 characters per minute. Express your answer using two significant figures.

The simplest of these cells would mimic red blood cells in that they could be filled with oxygen and then injected into a person’s bloodstream. The containers would slowly leak out the oxygen into the blood. Suppose these nanocells are cubic and 25 nm per side. What is the volume (in mL) of one nanocell?

7. A crystalline solid consists of atoms stacked up in a repeating lattice structure. Consider a crystal as shown in Figure P1.7a. The atoms reside at the corners of cubes of side L 5 0.200 nm. One piece of evidence for the regular arrangement of atoms comes from the flat surfaces along which a crystal separates, or cleaves, when it is broken. Suppose this crystal cleaves along a face diagonal as shown in Figure P1.7b. Calculate the spacing d between two adjacent atomic planes that sep- arate when the crystal cleaves.

The density of platinum is 21.45 x 103 kg/m3. a. Calculate the volume (in m3/atom) occupied per platinum atom b. Estimate the atomic diameter (in m);(The estimate uses the approximation that it is a cubic volume) c. Using this estimation, calculate the thickness of a metal foil (in m) containing 2.0 x 101 atomic layers of platinum.