QUESTION 3 [10]

With this problem, we want to explore the idea that, if it were not for drag, raindrops would attain fantastic speeds near Earth’s surface. Piet observes that the raindrops that are hitting him, have a radius of 2.00 mm and fall from a cloud located 1000 m above the ground he is laying on. Take the drag coefficient of the raindrops to be 0.50 and the ambient temperature to be 20.0 °C.

HINT: The area in the terminal velocity formula is a cross-sectional area of the object under consideration.

(a) Determine the terminal speed of the raindrops. You may assume spherical raindrops made out of water only. (4)

(b) Piet notices that the expression for the terminal speed used above does not contain explicit reference to the height of the cloud from whence the raindrops originate. Would the terminal speed for the raindrop in (a) be equal to that for a raindrop released 1.00 m above ground? Is there a discrepancy? Give reasons? (3)

(c) Determine the final velocity of the raindrop (in km/h) in when we ignore air resistance (3)

1. Imagine that it is year 2022 and our economy has been enduring a severe recession due to the current crisis. But then the U3 unemployment rate begins to decline. From this information alone, what should we conclude about the near-term outlook for the economy? Why? (To answer this question you will want to explain about the U3 unemployment rate and what could lead to this decline.)

2. Product X is made in a perfectly competitive industry that is initially in long-run equilibrium with a market price of $10 per unit. Suddenly (as has been the case with face masks and hand sanitizer) the demand for product X rises permanently.

Trace out the immediate short-run and ultimate long-run consequences for these items: price of product X market output of product X output of a typical company producing product X the profitability of companies in the market Explain why these items change in the way they do. (We are not given enough information to figure out exact amounts, just the direction of change.)

Design a single stage BJT amplifier with the following constraints:

This involves the following:

-DC and AC analysis and the frequency response of the amplifier.

-Use a 2N2222 transistor

-Power supply (VCC): 6 V

-An input impedance near to 3 kΩ

-Overall midband voltage gain of -30 V/V

-A load resistance of 2 kΩ

-The input signal has an RSignal of 500 Ω

-Choose a good Qpoint and select the coupling and bypass capacitors to obtain an fL-3dB of 100 Hz.

-The capacitors and resistors should have commercial values

-Part of the design requirement is that the amplifier will exhibit maximum symetrica1 swing in the voltage collector.

The Total Harmonic Distortion of the output voltage should be less than 5% when a sine wave with an amplitude of 5 mV is applied by the signal.

Determine the analytical fH-3dB of the final design of the amplifier. When the final design is completed, obtain the frequency response of the amplifier to verify the midband voltage gain, fL-3dB and fH-3dB.

QUESTION 8

If large numbers of individuals choose to behave as free riders, ________.

10 points   

QUESTION 9

A number of different government policies can increase the incentive to innovate, including:

10 points   

QUESTION 10

Which of the following would be classified as a situation where a third party benefits from a market transaction by others?

Europe’s response to the economic turmoil brought about by the global coronavirus shutdown is rekindling debate about the European Union’s financial unity. The euro has dropped 3.5% this year to $1.08, near its lowest level against the U.S. dollar since May 2017. The currency could lose another 5% by year-end, according to forecasts from Bank of America. That marks a sharp turnaround for a currency that posted its calmest year on record in 2019, when it slid 1.8%. The eurozone is headed for the deepest recession in its history, with the economy expected to contract 7.7% this year, the European Commission forecast on Wednesday. Any recovery is expected to be slow, halting and uneven, and is likely to lag that of the U.S. economy. Capital Economics, for instance, has forecast that the eurozone might not get back to pre-crisis levels until after 2022. Wall Street journal – May 14, 2020).

What are some of the major reasons for Euro to fall against dollar? Who appears be the winner of currency war United States or Europe?

A transparent cylindrical tube with radius r = 1.50 cm has a flat circular bottom and a top that is convex as seen from above, with radius of curvature of magnitude 2.60 cm. The cylinder is filled with quinoline, a colorless highly refractive liquid with index of refraction n = 1.627. Near the bottom of the tube, immersed in the liquid, is a luminescent LED display mounted on a platform whose height may be varied. The display is the letter A inside a circle that has a diameter of 1.05 cm. A real image of this display is formed at a height s′ above the top of the tube,

Part B

The luminescent object is moved up and down periodically so that the real image moves up and down in the air above the tube. A mist in the air renders this display visible and dramatic. If we want the image to move from 60.0 cm above the top of the cylinder to 1.00 m above the top of the cylinder during this motion, what is the corresponding range of motion for the object distance s? Find the minimum value of s. Express your answer with the appropriate units.

I have a digital watch, rated to go underwater to 100m. When it is underwater it can be read normally, up until you reach a certain angle, then suddenly, it becomes almost like a mirror, reflecting all the light that hits it, almost perfectly (you cannot read the digits, the entire surface becomes reflective.)

I've seen this happen with other waterproof watches too, so I don't think it's unique to mine or the specific model. I'm wondering what causes this? My physics teacher was stumped when I told him about this (we're doing lenses and imaging in physics right now.) I think it has something to do with internal refraction. I haven't been able to measure the angle it becomes reflective accurately, I estimate about 30-40 degrees. Near this critical point, it can be half and half reflective, where only half becomes a mirror, but it's always either reflective or not - never in between being reflective and non-reflective.

1. Batsheva sits on a spinning stool with her arms folded. What happens to her angular velocity if she

   does not move her body and the stool spins without friction

2. Eden and Ohad have the same mass. Eden sits at his desk in Rhode Island and Ohad sits at his desk in

   Ecuador (near the Equator). Who has more kinetic energy due to Earth’s rotation, Eden or Ohad, or is

   is the same

3. A space probe is launched from Earth and sent on a trip to the Moon, following a straight-line path.

   Is there a point along the way where the net gravitational force on the probe due to the Earth and

   Moon is zero, and if so is that point closer to the Earth or the Moon

4. Menachem Mendel and Moshe are the same weight and we wear identical shoes. When they both keep their feet on the ground, Menachem Mendel can lean forward farther than Moshe before falling. All other things being equal whose center of gravity is closer to the ground when both are standing straight

2. The three primary forms of business are sole proprietorships, partnerships, and corporations. You are contemplating starting a business. For each of the following proposals, explain which of the three types of businesses would be most appropriate. In each case describe the advantages and disadvantages of your choice.

(a) You are a music lover and are disgusted with the selection of compact discs available at the stores near your college. So, you decide to open up a store selling new and used compact discs.

(b) After a late night cram session, you and your roommate are in need of some pizza, but no restaurants are open. You decide to open an all night pizza parlor.

(c) You have an idea that will make you a billionaire before you graduate from college: a pizza delivery service - from any restaurant to any dorm. In order to make your revenue goal a reality, a local venture capital firm has informed you that you will need to nationally franchise your operation.