Refer to the zener diode datasheet. (a) What is the maximum dc power dissipation at $25^{\circ} \mathrm{C}$ for a $1 \mathrm{~N} 4738 \mathrm{~A}$ ? (b) Determine the maximum power dissipation at $70^{\circ} \mathrm{C}$ and at $100^{\circ} \mathrm{C}$ for a $1 \mathrm{~N} 4751 \mathrm{~A}$. (c) What is the minimum current required by the $1 \mathrm{~N} 4738 \mathrm{~A}$ for regulation? (d) What is the maximum current for the $1 \mathrm{~N} 4750 \mathrm{~A}$ at $25^{\circ} \mathrm{C}$ ? (e) The current through a $1 \mathrm{~N} 4740 \mathrm{~A}$ changes from $25 \mathrm{~mA}$ to $0.25 \mathrm{~mA}$. How much does the zener impedance change?

A student breaks a thermometer and spills most of the mercury (Hg) onto the floor of a laboratory that measures 15.2 m long, 6.6 m wide, and 2.4 m high. (a) Calculate the mass of mercury vapor (in grams) in the room at 20 degree C. The vapor pressure of mercury at 20 degree C is 1.7*10^(-6) atm. (b) Does the concentration of mercury vapor exceed the air quality regulation of 0.050 mg Hg/m3 of air? (c) One way to treat small quantities of spilled mercury is to spray sulfur powder over the metal. Suggest a physical and a chemical reason for this action.

Use the following information. The table shows regulation distances between hurdles in women's and men's races. In both the women's and men's events, the race consists of a straight track with 10 equally spaced hurdles.

$$\begin{matrix} \text{Event} & \text{Distance of Race} & \text{Distance from Start to First Hurdle} & \text{Distance Between Hurdles} & \text{Distance from Last Hurdle to Finish}\\ \text{Women's} & \text{100 m} & \text{13.00 m} & \text{8.50 m} & \square\\ \text{Men's} & \text{110 m} & \text{13.72 m} & \text{9.14 m} & \square\\ \end{matrix}$$

Find the distance from the last hurdle to the finish line for the men's race.

Target Corporation provides the following footnote relating to its retirement plans in its 2017 10-K report: Defined Contribution Plans Team members who meet eligibility requirements can participate in a defined contribution 401(k) plan by investing up to 80 percent of their eligible earnings. as limited by statute or regulation. We match 100 percent of each team member's contribution up to 5 percent of eligible earnings.

Company match contributions are made to funds designated by the participant, none of which are based on Target common stock. Benefits expense related to these matching contributions was $219 million,$197 million, and $224 million in 2017, 2016, and 2015, respectively.

b. How would Target account for its contributions to its retirement plan?

Target Corporation provides the following footnote relating to its retirement plans in its 2017 10-K report: Defined Contribution Plans Team members who meet eligibility requirements can participate in a defined contribution 401(k) plan by investing up to 80 percent of their eligible earnings. as limited by statute or regulation. We match 100 percent of each team member's contribution up to 5 percent of eligible earnings.

Company match contributions are made to funds designated by the participant, none of which are based on Target common stock. Benefits expense related to these matching contributions was $219 million,$197 million, and $224 million in 2017, 2016, and 2015, respectively.

d. Do you see any problems for employees in Target's plan?

Most of the following selections were taken from letters-to-the-editor columns of news papers and magazines. Identify any fallacies that may be committed, giving a brief explanation for your answer. Then, if a fallacy is identified, discuss the possible factors that led the arguer to commit the fallacy. A parent would never give a ten-year-old the car keys, fix him or her a martini, or let him or her wander at night through a dangerous part of town. The same holds true of the Internet. Watch what children access, but leave the Net alone. Regulation is no substitute for responsibility.

A student breaks a thermometer and spills most of the mercury $(\mathrm{Hg})$ onto the floor of a laboratory that measures $15.2 \mathrm{~m}$ long, $6.6 \mathrm{~m}$ wide, and $2.4 \mathrm{~m}$ high.

(a) Calculate the mass of mercury vapor (in grams) in the room at $20^{\circ} \mathrm{C}$. The vapor pressure of mercury at $20^{\circ} \mathrm{C}$ is $1.7 \times 10^{-6}$ atm.

(b) Does the concentration of mercury vapor exceed the air quality regulation of $0.050 \mathrm{mg} \mathrm{Hg} / \mathrm{m}^3$ of air?

(c) One way to deal with small quantities of spilled mercury is to spray sulfur powder over the metal. Suggest a physical and a chemical reason for this action.

The table shows regulation distances between hurdles in woman's and men's races. In both the women's and men's events, the race consists of a straight track with 10 equally spaced hurdles.

$$\begin{matrix} \text{Event} & \text{Distance of Race} & \text{Distance from Start to First Hurdle} & \text{Distance Between Hurdles} & \text{Distance from last Hurdle to Finish}\\ \text{Women's} & \text{100 m} & \text{13.00 m} & \text{8.50 m} & \text{ }\\ \text{Men's} & \text{110 m} & \text{13.72 m} & \text{9.14 m} & \text{ }\\ \end{matrix}$$

Find the distance from the last hurdle to the finish line for the woman's race.

A sporting goods manufacturer produces regulation soccer balls at two plants. The costs of producing $x_1$ units at location 1 and $x_2$ units at location 2 are given by $C_1\left(x_1\right)=0.02 x_1^2+4 x_1+500$ and

$$C_2\left(x_2\right)=0.05 x_2^2+4 x_2+275$$

respectively. If the product sells for $50 per unit, then the profit function for the product is given by

$$P\left(x_1, x_2\right)=50\left(x_1+x_2\right)-C_1\left(x_1\right)-C_2\left(x_2\right) .$$

Find P(300,200).

A least-squares regression line was used to model the relationship between putting average (on greens hit in regulation) and scoring average for golfers on the 2009 PGA tour. The corresponding residual plot is shown below.

a) Based on the residual plot, is a linear model appropriate for this association? Explain.

b) The point highlighted in red is for the golfer David Duval. Estimate his residual from the graph and interpret its value.

c) If you were to predict the scoring average for a golfer with a putting average of $1.86$, would you expect your prediction to be too low, too high, or just about right? Explain.

A sporting goods manufacturer produces regulation soccer balls at two plants. The costs of producing $x_1$ units at location 1 and $x_2$ units at location 2 are given by $C_1\left(x_1\right)=0.02 x_1^2+4 x_1+500$ and

$$C_2\left(x_2\right)=0.05 x_2^2+4 x_2+275$$

respectively. If the product sells for $50 per unit, then the profit function for the product is given by

$$P\left(x_1, x_2\right)=50\left(x_1+x_2\right)-C_1\left(x_1\right)-C_2\left(x_2\right) .$$

Find P(250,150).

Match the skin structures in column B with their function listed in column A.
Column A$\hspace{5cm}$ Column B
(1) protection from ultraviolet radiation $\hspace{1cm}$(a) dendritic cells
(2) insulation, energy storage$\hspace{2.5cm}$(b) dermal vascular plexuses
(3) waterproofing and prevention of water loss$\hspace{0.5cm}$ (c) papillary layer of the dermis
(4) temperature regulation$\hspace{3cm}$ (d) hypodermis
(5) initiation of an immune response to invading bacteria $\hspace{0.4cm}$(e) melanocytes
(6) excretion of water, urea, and salts$\hspace{2cm}$(f) stratum corneum
(7) help in bonding the epithelium to the dermis$\hspace{2cm}$(g) eccrine sweat glands
$\hspace{7cm}$(h) reticular layer of the dermis

A species of bacteria can synthesize the amino acid histidine so it does not require histidine in its growth medium. A key enzyme, which we will call histidine synthetase, is necessary for histidine biosynthesis. When these bacteria are given histidine in their growth media, they stop synthesizing histidine intracellularly. Based on this observation alone, propose three different regulatory mechanisms to explain why histidine biosynthesis ceases when histidine is in the growth medium. To explore this phenomenon further, you measure the amount of intracellular histidine synthetase protein when cells are grown in the presence and absence of histidine. In both conditions, the amount of this protein is identical. Which mechanism of regulation would be consistent with this observation?

Wood bats are required in professional baseball but metal bats are sometimes allowed in youth and college baseball. One result is that the exit speed $v$ of the baseball off a metal bat can be greater. In one set of measurements under the same circumstances, $v=50.98 \mathrm{~m} / \mathrm{s}$ off a wood bat and $v=61.50 \mathrm{~m} / \mathrm{s}$ off a metal bat. Consider a ball hit directly toward the pitcher. The regulation distance between pitcher and batter is $\Delta x=60 \mathrm{ft} 6$ in. For those measured speeds, how much time $\Delta t$ does the ball take to reach the pitcher for $(a)$ the wood bat and $(b)$ the metal bat? $(c)$ By what percentage would $\Delta t$ be reduced if professional baseball switched to metal bats? Because pitchers do not wear any protective equipment on face or body, the situation is already dangerous and the switch would add to that danger.