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## Flu Season Physics

A virus is sneezed out at a rate of 45 m/s. It travels through the air and makes contact with a stationary person nearby. The stationary person appears unaffected. Which of the following statements is always true?

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## That’s Why They Wear Helmets

A human skull can withstand 100 kPa before fracturing. A baseball, with an impact area 0.003 m2 and a weight of 0.15 kg, is launched from a pitching machine, a distance of 20 meters, towards a skull. How long would it take for the baseball to travel if the skull was cracked?

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## Golden Romance

Your significant other gave you a watch for Valentine ’s Day, and tells you it’s made of “pure gold” (density of gold = 19,000 kg/m3). Being a mistrusting boy/girl friend, you decide to find out whether this is true. Later that day, you place the watch on a spring scale and lower it into water. The weight on the scale reads 10N out of water and 6N when completely submerged. Is the watch really made out of pure gold?

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## Burn Out

A patient in a wheelchair notices his wheels are sometimes warm after he travels. If the patient traverses the same distance across the same material surface, which situation would his wheels be the hottest after completion?

## Heat Transfer Due to Conduction

The human body has an average temperature of 37°C. A person, with a fever of 40°C, would like to know what will be the temperature of her skin in an ice bath, after reaching a steady state. Which of the following equations can be used to create an analogous formula for heat transfer due to conduction?

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There are 125 million rod cells in one human eye. Each rod cell is sensitive enough to respond to one photon of power P. Knowing that surface area of the retina is 0.00125 m2, and that it takes 20% of the rod cells to become simultaneously active to exhibit a flash of blindness, what is the intensity of light required to blind both eyes?

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## Depolarize the Pacemaker Cells, Using Physics!

A defibrillator is used to depolarize the pacemaker cells, allowing the sinoatrial node to reestablish a normal rhythm. A heart enters ventricular fibrillations and requires 30 amps. In essence, the defibrillator is a discharging capacitor, of C farads, across a patient with a resistance of R ohms. If the defibrillator started at a full charge, emitting 30 amps, how much time elapses before the current drops below 25 amps?

Eq. 1 – Discharge Formula

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## Holes in Pipes 2

A barrel of water with radius of 2.0 m sits on top of an 8-meter-high wall. A hole of radius 1 cm forms about 5 m down from the level of the water in the barrel. What is the velocity of the water as it leaves the hole? Use a water flow approach. Remember that Bernoulli’s equation is:
p1 + pgy1 + (1/2)pv12 = p2 +pgy2 + (1/2)pv22

## Holes in Pipes

A length of piping connects the rain gutters on a house roof to the drain in the ground. The house is 3 stories, or about 8 meters in height. If a hole forms in the pipe at the midpoint, approximately what will the velocity of the water be as it escapes through the hole? Ignore water flow and use kinematics.

## Ionize DNA in Tumor Cells

Radiation therapy uses high energy photons to ionize the DNA in malignant cells. If UVB light has enough energy to create pyrimidine dimers, what part of the electromagnetic spectrum can be used for its curative, higher energy effects.

I.) X-rays and gamma rays.
II.) Radio waves and micro waves.
III.) NIR and Green light.