The effect of temperature change on the electrical conductivity of ultrapure silicon is quite different from that on silicon containing a minute trace of arsenic. Why is this so?

(A) Find the linear, quadratic, and logarithmic functions that best fit the data points $(1,3.2), (2,4.2), (3,4.7), (4,5.0)$, and $(5,5.3)$. (Round coefficients to two decimal places.)

(B) Which of the three functions best fits the data? Explain.

Think About It A person has two job offers. The starting salary for each is 30,000, and after 10 years of service each will pay 56,000. The salary increases for each offer are shown in the figure. From a strictly monetary viewpoint, which is the better offer? Explain.

True or false? Void functions do not return any value when they are called.

A constant-volume tank contains 30 kg of nitrogen at 900 K, and a constant-pressure device contains 15 kg of argon at 300 K. A heat engine placed between the tank and device extracts heat from the high-temperature tank, produces work, and rejects heat to the low-temperature device. Determine the maximum work that can be produced by the heat engine and the final temperatures of the nitrogen and argon. Assume constant specific heats at room temperature.

The man $A$ has a weight of $175 \mathrm{lb}$ and jumps from rest at a height $h=8 \mathrm{ft}$ onto a platform $P$ that has a weight of $60 \mathrm{lb}$. The platform is mounted on a spring, which has a stiffness $k=200 \mathrm{lb} / \mathrm{ft}$. Determine (a) the velocities of $A$ and $P$ just after impact and (b) the maximum compression imparted to the spring by the impact. Assume the coefficient of restitution between the man and the platform is $e=0.6$, and the man holds himself rigid during the motion.

A manufacturer of detergent claims that the contents of boxes sold weigh on average at least 16 ounces. The distribution of weight is known to be normal, with a standard deviation of 0.4 ounce. A random sample of 16 boxes yielded a sample mean weight of 15.84 ounces. Test at the 10% significance level the null hypothesis that the population mean weight is at least 16 ounces.

Determine the change in the internal energy of air, in kJ/kg, as it undergoes a change of state from 100 kPa and $20^{\circ} \mathrm{C}$ to 600 kPa and $300^{\circ} \mathrm{C}$ using the equation of state P(v - a) = RT where $a=0.10\ \mathrm{m}^{3} / \mathrm{kg},$ and compare the result to the value obtained by using the ideal gas equation of state.

A diffraction grating has 2000 lines per centimeter. At what angle will the first-order maximum be for 520-nm- wavelength green light?

A drop of liquid is placed on a surface. A particle of the liquid at the contact point is subject to a cohesive force of 4.00 N directed $52.0 ^ { \circ }$ above the surface. If the contact angle is $104 ^ { \circ }$, what is the magnitude of the adhesive force between the particle and the surface?

The five stages of the Program Development Cycle are: Design the program, __________, Correct syntax errors, __________, Correct logic errors. a. Write the code, Correct font b. Test the code, Write the code c. Write the code, Test the code d. Correct generic errors, Correct all errors

The cost function for production of a commodity is

$$C(x)=339+25x-0.09x^2+0.0004x^3$$

Compare C’(100) with the cost of producing the 101st item.

If astronauts could travel at v = 0.95c, we on Earth would say it takes (4.2/0.95) = 4.4 years to reach Alpha Centauri, 4.2 lightyears away. The astronauts disagree. (a) How much time passes on the astronauts’ clocks? (b) What distance to Alpha Centauri do the astronauts measure?

Find the indicated probabilities. If convenient, use technology to find the probabilities. In a survey of U.S. men, the heights in the 20 - 29 age group were normally distributed, with a mean of 69.4 inches and a standard deviation of 2.9 inches. Find the probability that a randomly selected study participant has a height that is (a) less than 66 inches, (b) between 66 and 72 inches, and (c) more than 72 inches, and (d) identify any unusual events. Explain your reasoning.