The frequency distribution shows the number of medical tests conducted on 30 randomly selected emergency room patients.

Number of tests performed	Number of patients
0	11
1	9
2	5
3	4
4 or more	1

If a patient is selected at random, find these probabilities:

a. The patient had exactly 3 tests done. b. The patient had at most 2 tests done. c. The patient has 1 or 2 tests done. d. The patient had fewer than 3 tests done. e. The patient had at least 3 tests done.

As a young design engineer you are asked to design an emergency braking parachute system for use with a military aircraft of mass 9500 kg. The plane lands at 350 km/hr, and the parachute system alone must slow the airplane to 100 km/hr in less than 1200 m. Find the minimum diameter required for a single parachute, and for three noninterfering parachutes. Plot the airplane speed versus distance and versus time. What is the maximum “g-force” experienced?

The following table, reproduced from earlier exercise, gives the probability distribution of the number of patients who enter Millard Fellmore Memorial Hospital's emergency room in a given hour.

$$\begin{array}{l|ccccccc} \hline \text { Patients per hour } & 0 & 1 & 2 & 3 & 4 & 5 & 6 \\ \hline \text { Probability } & .2725 & .3543 & .2303 & .0998 & .0324 & .0084 & .0023 \\ \hline \end{array}$$

Calculate this probability distribution's mean and standard deviation.

An accident victim who had not been wearing a seat belt received trauma to his forehead when he was thrown against the windshield. The physicians in the emergency room worried that his brain stem may have been driven inferiorly through the foramen magnum. To help assess this, they quickly took a standard X-ray film of his head and searched for the position of the pineal gland. How could anyone expect to find this tiny, boneless gland in a radiograph?

The frequency distribution shown here illustrates the number of medical tests conducted on 30 randomly selected emergency patients.

If a patient is selected at random, find these probabilities.

a. The patient has had exactly 2 tests done.

b. The patient has had at least 2 tests done.

c. The patient has had at most 3 tests done.

d. The patient has had 3 or fewer tests done.

e. The patient has had 1 or 2 tests done.

Trapped on a deserted island, you salvage some copper wire and a generator to build a makeshift radio transmitter. (a) If you wrap the wire into an $8$-turn coil of radius $3.8 \mathrm{~cm}$ and length $25 \mathrm{~cm}$, what is its inductance? (b) What capacitance do you need to make an $RLC$ circuit with the coil that oscillates at the emergency beacon frequency of $406 \mathrm{MHz}$ ? (c) If you fashion the parallel-plate capacitor out of two aluminum squares, $5.0 \mathrm{~cm}$ on a side, what should be the separation distance between the two plates?

A car passenger buckles himself in with a seat belt and holds his $18-\mathrm{kg}$ toddler on his lap. Use the work-energy principle to answer the following questions. (a) While traveling $25\mathrm{~m}/\mathrm{s}$, the driver has to make an emergency stop over a distance of $45\mathrm{~m}$. Assuming constant deceleration, how much force will the arms of the parent need to exert on the child during this deceleration period? Is this force achievable by an average parent?

B.L., 17, had a compression fracture at the C5-C6 after jumping into a river from a bridge and slamming into a submerged rock. Fortunately, she was saved by a companion who had first-aid expertise and worked to limit any collateral damage. B.L. was unable to move her limbs, feel touch, or have reflexes in her limbs when she arrived at the emergency room. Describe the causes and ways in which B.L.'s ability to breathe may be hampered at any time.

Walking to her car after her 65th birthday party, Mrs. Schultz tripped on ice and fell forward on her outstretched palms. When she arrived at the emergency room, her right wrist and hand were bent like a fork. Dr. Jefferson felt that the styloid process of her radius was outside of the anatomical snuff box and slightly proximal to the styloid process of the ulna. When he checked her elbow, he found that the olecranon lay 2 cm proximal to the two epicondyles of the right humerus. Explain all these observations, and describe what had happened to Mrs.Schultz’s limb.

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 driver makes an emergency stop and inadvertently locks up the brakes of the car, which skids to a stop on dry concrete. Consider the effect of heavy rain on this scenario. Using the values in Table 1, determine how much farther the car would skid (expressed as a percentage of the dry-weather skid) if the concrete were wet instead. What does this question imply about driving safely?

Table 1 Coeffi cients of Kinetic Friction for Rubber on Concrete

The flywheel of an old steam engine is a solid homogeneous metal disk of mass $M=120 \mathrm{~kg}$ and radius $R=80.0 \mathrm{~cm}$. The engine rotates the wheel at 500 . rpm. In an emergency, to bring the engine to a stop, the flywheel is disengaged from the engine and a brake pad is applied at the edge to provide a radially inward force $F=100$. N. If the coefficient of kinetic friction between the pad and the flywheel is $\mu_{\mathrm{k}}=0.200$, how many revolutions does the flywheel make before coming to rest? How long does it take for the flywheel to come to rest? Calculate the work done by the torque during this time.

Doctors treated a patient at an emergency room from 2:00 P.M. to 7:00 P.M. The patient’s blood oxygen level L (in percent) during this time period can be modeled by $L=-0.270 t^{2}+3.59 t+83.1, \quad 2 \leq t \leq 7$ where t represents the time of day, with t=2 corresponding to 2:00 P.M. Use the model to estimate the time (rounded to the nearest hour) when the patient’s blood oxygen level was 93%.

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.

Eighteen hours after the injury, the NAP reports these vital signs for A.N. and states that the urine output for the past hour was $20$ mL.

$$\begin{aligned} &\text { Vital Signs }\\ &\begin{array}{ll} \text { Blood pressure } & 90 / 50 \mathrm{~mm} \mathrm{Hg} \\ \text { Heart rate } & 110 \text { beats } / \mathrm{min} \\ \text { Respiratory rate } & 24 \text { breaths } / \mathrm{min} \end{array} \end{aligned}$$

What do you suspect is occurring, and why does this concern you?