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.

A planning engineer for a new alum plant must present some estimates to his company regarding the capacity of a silo designed to store bauxite ore until it is processed into alum. The ore resembles pink talcum powder and is poured from a conveyor at the top of the silo. The silo is a cylinder 100 ft high with a radius of 200 ft. The conveyor carries ore at a rate of 60,000 $\pi \mathrm{ft}^{3} / \mathrm{h}$ and the ore maintains a conical shape whose radius is 1.5 times its height. If, at a certain time t, the pile is 60 ft high, how long will it take for the pile to reach the top of the silo?

A parallel-plate capacitor has capacitance $C_0=5.00 \mathrm{pF}$ when there is air between the plates. The separation between the plates is $1.50 \mathrm{~mm}$. $(a)$ What is the maximum magnitude of charge $Q$ that can be placed on each plate if the electric field in the region between the plates is not to exceed $3.00 \times 10^4 \mathrm{~V} / \mathrm{m}$ ? $(b)$ A dielectric with $K=2.70$ is inserted between the plates of the capacitor, completely filling the volume between the plates. Now what is the maximum magnitude of charge on each plate if the electric field between the plates is not to exceed $3.00 \times 10^4 \mathrm{~V} / \mathrm{m}$ ?

The 60-Hz line voltage for a 60-kW, 0.76-pf lagging industrial load is 240$\angle 0^{\circ}$ V rms. Find the value of capacitance that when placed in parallel with the load will raise the power factor to 0.9 lagging.

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.

a. Does Target have a defined contribution or defined benefit pension plan? Explain.

(a) For a circuit, the parameters are $R_S=2 \mathrm{k} \Omega$ and $R_P=8 \mathrm{k} \Omega$. (i) If the corner frequency is $f_L=50 \mathrm{~Hz}$, determine the value of $C_S$. (ii) Find the magnitude of the transfer function at $f=20 \mathrm{~Hz}, 50 \mathrm{~Hz}$, and $100 \mathrm{~Hz}$. (b) Consider a circuit with parameters $R_S=4.7 \mathrm{k} \Omega$, $R_P=25 \mathrm{k} \Omega$, and $C_P=120 \mathrm{pF}$. (i) Determine the corner frequency $f_H$. (ii) Determine the magnitude of the transfer function at $f=0.2 f_H, f=f_H$, and $f=8 f_H$.

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.

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).

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 men's race.

You and a partner are asked to complete a lab entitled "Oxides of Ruthenium" that is sched uled to extend over two lab periods. The first lab, which is to be completed by your partner, is devoted to carrying out composition al an alysis. In the second lab, you are to determine melting points. Upon going to lab you find two unlabeled vials, one containing a soft yellow substance and the other a black powder. You also find the following notes in your partner's notebook Compound 1: 76.0% Ru and 24.0% O (by mass), Compound 2 : 61.2% Ru and 38.8% O (by mass) What is the identity of the black compound?

A planning engineer for a new alum plant must present some estimates to his company regarding the capacity of a silo designed to store bauxite ore until it is processed into alum. The ore resembles pink talcum powder and is poured from a conveyor at the top of the silo. The silo is a cylinder 100 ft high with a radius of 200 ft. The conveyor carries ore at a rate of 60,000 $\pi \mathrm{ft}^{3} / \mathrm{h}$ and the ore maintains a conical shape whose radius is 1.5 times its height. How much room will be left in the floor area of the silo when the pile is 60 ft high? How fast is the floor area of the pile growing at the height?

The thermite process is used for welding railway track together. In this reaction, aluminum reduces iron(III) oxide to metallic iron:

$$2 AI(s) + Fe2O3(s)→2 Fe(s) + Al2O3(s)$$

Igniting a small charge of barium peroxide mixed with aluminum triggers the reaction of a mixture of aluminum powder and iron (III) oxide; the molten iron produced flows into the space between the steel rails that are to bejoined. (a) Calculate the standard enthalpy change ΔH° for this reaction, using data from Appendix D. (b) Calculate the heat given off when 3.21 g iron(III) oxide is reduced by aluminum at constant pressure.

Use the following information for this exercise .

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.

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

You and a partner are aske d to complete a lab entitled "Oxides of Ruthenium" that is sched uled to extend over two lab periods. The first lab, which is to be completed by your partner, is devoted to carrying out compositional analysis. In the second lab, you are to determine melting points. Upon going to lab you find two unlabeled vials, one containing a soft yellow substance and the other a black powder. You also find the following notes in your partner's notebook Compound 1: 76.0% Ru and 24.0% 0 (by mass), Compound 2 : 61.2% Ru and 38.8% 0 (by mass) . What is the empirical formula for Compound 1?