Consider a simple elevator design in which a 15,000 kg car A is connected to a 12,000 kg counterweight B. Suppose that a failure of the drive system occurs (the failure does not affect the rope connecting A and B) when the car is at rest and 50 m above its buffer, causing the elevator car to fall. Model the car and the counterweight as particles and the cord as massless and inextensible, and model the action of the emergency brakes using a Coulomb friction model with kinetic friction coefficient $\mu \mathrm{k}=0.5$ and a normal force equal to 35% of the car’s weight. Determine the speed with which the car impacts the buffer.

A patient is admitted to the emergency department with suspected carbon monoxide poisoning. Even though the patient's color is ruddy and not cyanotic, the nurse understands the patient is at a risk for decreased oxygen-carrying capacity of blood because carbon monoxide does which of the following:

1. Stimulates hyperventilation, causing respiratory alkalosis
2. Forms a strong bond with hemoglobin, thus preventing oxygen binding in the lungs
3. Stimulates hypoventilation, causing respiratory acidosis
4. Causes alveoli to overinflate, leading to atelectasis

J.R. is a 28-year-old man who was doing home repairs. He fell from the top of a 6-foot stepladder, striking his head on a large rock. He experienced a momentary loss of consciousness. By the time his neighbour got to him, he was conscious but bleeding profusely from a laceration over the right temporal area. The neighbour drove him to the emergency department of your hospital. As the nurse, you immediately apply a cervical collar, lay him on a stretcher, and take J.R. to a treatment room.
What steps will you take to assess J.R.?

A traffic engineer determines that the number of cars passing through a certain intersection each week can be modeled by $C(x)=0.02x^3+0.4x^2+0.2x+35$, where x Is the number of weeks since the survey began. A new road has just opened that affects the traffic at that intersection. Let $N(x)=C(x)+200$.
Emergency roadwork temporarily closes off most of the traffic to this intersection. Write a function R(x) that could model the effect on C(x) Explain how the graph of C(x) might be transformed into R{x).

Review the events listed under "Migration and Settlement" on the thematic timeline on page 237, and then discuss how southern expansion, the end of the Atlantic slave trade in 1808, and the subsequent rise of the internal slave trade affected the experiences and identities of the African American population.

An emergency cell phone charger requires you to turn a small crank in order to create the energy needed to recharge the phone’s battery. If you turn the crank 120 times per minute, the total number r of revolutions that you turn the crank is given by r = 120t where t is the time (in minutes) spent turning the crank. a. Graph the function and identify its domain and range. b. Identify the domain and range if you stop turning the crank after 4 minutes. Explain how this affects the appearance of the graph.

Potassium superoxide, $KO_2$, is employed in a self-contained breathing apparatus used by emergency personnel as a source of oxygen. The reaction is\

$4KO_2(s) + 2H_2O(l) \longrightarrow 4KOH(s) + 3O_2(g)$\

Say a self-contained breathing apparatus is charged with 750 g $KO_2$ and then is used to produce 195 g of oxygen. Was all of the $KO_2$ consumed in this reaction? If the $KO_2$ wasn’t all consumed, how much is left over and what mass of additional $O_2$ could be produced?

You are working in the emergency department (ED) of a community hospital when the ambulance arrives with A.N., an $18$-year-old woman who was caught in a house fire. She was sleeping when the fire started and managed to make her way out of the house through thick smoke. The emergency medical system crew initiated humidified oxygen at $15 \mathrm{~L} / \mathrm{min}$ per nonrebreather mask and started a $16$-gauge IV with lactated Ringer's solution. On arrival to the ED, her vital signs are $100/66, 125, 34$, $\mathrm{SaO}_2 93 \%$. An additional $16$-gauge IV is inserted. She appears anxious and in pain.

$$\begin{aligned} &\text { Laboratory Test Values }\\ &\begin{array}{ll} \text { Hgb } & 20 \mathrm{~g} / \mathrm{dL} \\ \text { Hct } & 51 \% \\ \mathrm{~K} & 4.9 \mathrm{mEq} / \mathrm{dL} \\ \mathrm{Na} & 133 \mathrm{mEq} / \mathrm{dL} \\ \mathrm{Cl} & 100 \mathrm{mEq} / \mathrm{dL} \\ \text { Glu } & 159 \mathrm{mg} / \mathrm{dL} \\ \text { BUN } & 28 \mathrm{mg} / \mathrm{dL} \\ \text { Cre } & 1.0 \mathrm{mg} / \mathrm{dL} \end{array} \end{aligned}$$

Interpret A.N.'s laboratory results.

While playing on her swing set, 10-year-old Yasmin falls and breaks her right leg. At the emergency room, the physician tells Yasmin's parents that the proximal end of the tibia, where the epiphysis meets the diaphysis, is fractured. The fracture is properly set and eventually heals. During a routine physical when she is 18 , Yasmin learns that her right leg is $2 cm$ shorter than her left, probably because of her accident. What might account for this difference?

Which of the following most directly changed the legal status of African Americans established by the Supreme Court's Dred Scott v Sandford decision? a. Emancipation Proclamation (1862) b. Thirteenth Amendment (1865) c. Fourteenth Amendment (1868) d. Fifteenth Amendment (1870)

Let X denote the number of times a certain numerical control machine will malfunction: 1, 2, or 3 times on any given day. Let Y denote the number of times a technician is called on an emergency call. Their joint probability distribution is given as

$$\begin{matrix} & & & x & \\ \hline & & 1 & 2 & 3 \\ & 1 & 0.05 & 0.05 & 0.10 \\ y & 3 & 0.05 & 0.10 & 0.35 \\ & 5 & 0.00 & 0.20 & 0.10 \end{matrix}$$

(a) Evaluate the marginal distribution of X. (b) Evaluate the marginal distribution of Y. (c) Find P(Y=3|X=2).

Large stadiums rely on backup generators to provide electricity in the event of a power failure. Assume that emergency backup generators fail 22% of the times when they are needed (based on data from Arshad Mansoor, senior vice president with the Electric Power Research Institute). A stadium has three backup generators so that power is available if at least one of them works in a power failure. Find the probability of having at least one of the backup generators working given that a power failure has occurred. Does the result appear to be adequate for the stadium's needs?

Define Type I and Type II error for each scenario, and identify the cost(s) of each type of error.

Approaching O'Hare for landing, a British Air flight from London has been in a holding pattern for $45$ minutes due to bad weather. Landing is expected within $15$ minutes. The flight crew could declare an emergency and land immediately, but an FAA investigation would be launched and other flights might be endangered. The null hypothesis is that there is enough fuel to stay aloft for $15$ more minutes.

Ambulance response time. Ambulance response time is measured as the time (in minutes) between the initial call to emergency medical services (EMS) and when thepatient is reached by ambulance. Geographical Analysis (Vol. 41, 2009) investigated the characteristics of ambulance response time for EMS calls in Edmonton, Alberta. For a particular EMS station (call it Station A), ambulance response time is known to be normally distributed with $\mu=7.5$ minutes and $\sigma=2.5$ minutes. A randomly selected EMS call in Edmonton has an ambulance response time of 2 minutes. Is it likely that this call was serviced by Station A? Explain.