Air consumption for a 4-stroke SI engine is measured by means of a circular orifice of diameter 30 mm. The Cd for the orifice is 0.63 and the pressure across the orifice is 155 mm of water. The barometer reads 750 mm of Hg. Temperature of air in the room is 37oC. The piston displacement volume is 1780 cc. the compression ratio is 6.8. The fuel consumption is 8 kg/hr and having heating value of 43.6 MJ/kg. The BP developed at 2500 rpm is 28 kW. Determine, (a) volumetric efficiency,

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Air consumption for a 4-stroke SI engine is measured by means of a circular orifice of
diameter 30 mm. The Cd for the orifice is 0.63 and the pressure across the orifice is 155 mm
of water. The barometer reads 750 mm of Hg. Temperature of air in the room is 37oC. The
piston displacement volume is 1780 cc. the compression ratio is 6.8. The fuel consumption is
8 kg/hr and having heating value of 43.6 MJ/kg. The BP developed at 2500 rpm is 28 kW.
Determine, (a) volumetric efficiency, (b) air-fuel ratio, (c) brake mep, and (d) relative
efficiency on the brake thermal efficiency basis.
Do you think Pluto should still be designated a planet, or not? What about the other four classified dwarf planets? Consider the IAU definition and the characteristics of both planets and small bodies in the Solar System, and defend your position.

1) What is an electric field? Sketch the shape of the electric field around a single proton.

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1) What is an electric field? Sketch the shape of the electric field around a single proton.
2) If a uniform electric field is pointing east, what is the direction of the force on an electron? What is the direction of force on a positive particle?
3) If electrons are flowing counter clock wise in a circuit, which way is the conventional current flowing?
4) Explain what current, voltage, and resistance are?
5) Describe the differences between circuits with resistors connected in series vs. parallel.
Problems (show your work)
1) Two charged particles exert an electrical force of 16 N on each other. What will the magnitude of the force be if the distance between them is reduced by half? What if the distance is doubled?
2) What would the separation between two particles each with a charge of 1 C have to be so that they each feel a force of 1 N.
3) A particle with a charge of 2.0 x 10-6 C experiences an upward force of 8N. What is the magnitude and direction of the electric field at that point? What if the charge was negative?
4) During 30 second of use, 250 C of charge flow through a microwave over. What is the current?
5) A current of 12 A flows through an electric heater operating on 120 V. What is the heater’s resistance?
6) The resistance of each brake light on an automobile is 6.6 Ω. Use the fact that cars have 12 V electrical systems to calculate the current that flows through each bulb.
7) An electric eel can generate a 400 V, 0.5 A shock for stunning its prey. What is the eel’s power output?
8) A clock consumes 2 W of electrical power. How much energy does it use each day?
Challenge (show work)
1) Three particles each with a charge of 2.5 x 10-6 C are located on the x-axis. There coordinates are (0,0), (2,0), and (6,0). What is the magnitude and direction of the electrical force on the particle located at (2,0)?
Chapter 8
Questions (use complete sentences)
1) Sketch the shape of the magnetic field around a bar magnet.
2) List the main type of electromagnetic waves in order of increasing frequency.
3) How does the radiation emitted by a black body change as its temperature increases?
4) What does a transformer do?
5) What are the three observations of magnetism talked about in class?
Problems (show work)
1) A cell phone charger is a transformer that reduces 120 V to 5V. For each 1,000 turns in the input coil, how many turns are there in the output coil?
2) What is the wavelength of a 60,000 Hz radio wave?
3) A transformer has an input coil of 2,000 turns, and an output coil of 500 turns. If 120 V is connected to the input coil how much voltage will it output?
4) Compute the frequency of an EM wave with a wavelength of 0.0542 m.
5) How much more energy would a black body radiate at 900 K vs 300 K?
6) What wavelength of light do humans mostly radiate if the human body temperature is 310 K?
Chapter 9
Questions (use complete sentences)
1) Describe how the path of a ray is deviated as it passes from one medium to another in which the speed of light is lower. Contrast this with the case when the speed of light in the second medium is higher.
2) A light ray in air enters a block of plastic as shown below. Which of the numbered paths is the correct one for the ray in the plastic?
Image result for a light ray in air enters a block
3) What is total internal refection, and how is it related to the critical angle?
4) What is the difference between a converging and diverging lens?
Problems (show your work)
1) A light ray traveling in air strikes the surface of a flat glass block at an angle of 50°. Part of the light is reflected and part is refracted. What are the angles of reflection and refraction?
2) Compute the index of refraction of (a) air, (b) benzene, and (c) crown glass.
3) A camera is equipped with a lens of 30 cm. When an object 200 cm away is being photographed, how far from the lens should the film be placed?
4) A 2 cm tall object stands in front of a converging lens. It is desired that a virtual image 2.5 times larger than the object be formed. How far form the lens must the object be placed to accomplish this task, if the final image is located 15 cm from the lens?
5) When viewed from a magnifying glass, a stamp that is 2 cm wide appears upright and 6 cm wide. What is the magnification?
6) A small object is placed to the left of a convex lens and on its optical axis. The object is 30 cm from the lens, which has a focal length of 10 cm. Determine the location of the image. Describe the image.
7) Solve number 6 again but replacing the convex lens with a diverging lens of focal length 10cm.

1) Falling objects subject to aerodynamic drag accelerate initially but then reach what is called a terminal velocity. The motion from this point on is at constant velocity. Consider the motion of an object that has reached a terminal velocity of 28.6 m/s (down) at a height of 230m. If x=0 (the origin) is at ground level and “up” is the positive direction:

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1) Falling objects subject to aerodynamic drag accelerate initially but then reach what is called a terminal velocity. The motion from this point on is at constant velocity. Consider the motion of an object that has reached a terminal velocity of 28.6 m/s (down) at a height of 230m. If x=0 (the origin) is at ground level and “up” is the positive direction:
a) Write out xf =xi + vit for this motion leaving x and t as variables. The data given represents the t = 0 motion state.
b) Use the equation formulated in part (a) to determine the t value at which the object is 50 m high, and the t value at which the object hits the ground.
2) Three students formulate equations to solve the following problem. A lunar lander is making its descent to Moon Base I. The lander descends slowly under the retro-thrust of its descent engine. The engine is cut off when the lander is 5.0 m above the surface and has a downward speed of 0.8 m/s. With the engine off, the lander is in free fall.
Each uses a different coordinate system to describe the motion depicted in the problem statement and formulates both a position, y, and a velocity v, equation.
Student 1: y = (0.8 m/s)t + 1/2gt2, v = (0.8 m/s) + gt
Student 2: y = 5.0 m – (0.8 m/s)t – 1/2gt2, v = -(0.8 m/s) – gt
Student 3: y = – (0.8 m/s)t – 1/2gt2, v = -(0.8 m/s) – gt
The equations are based on the general forms:
y = yi + vit+ 1/2at2 and
v = vi + at . And all three formulations are “correct”. In each equation g=+1.6 m/s2 and the initial conditions (t=0) describe the lander 5.0 m from the surface moving downward at 0.8 m/s.
a) In formulating his or her two equations each student had to choose a real world position of the origin (the position of y=0) relative to the lunar surface, and a real world direction at which the y axis points (either up or down). Draw a diagram for each formulation showing the position of the origin relative to the lunar surface and the real world direction at which the y axis points. Briefly explain your reasoning in each case.
b) Each student solves for the t value at which the lander reaches the lunar surface by setting y equal to the position of the lunar surface in his or her chosen coordinate system. What value of y does each student use?
c) Use student 3’s formulation and solve for the t and v values of the lander just as it reaches the lunar surface. That is, solve the problem with student #3’s formulation.
3. You have a job working for a University research group investigating ozone depletion in the atmosphere. The plan is to collect data on the chemical composition of the atmosphere as a function of the distance from the ground using a mass spectrometer located in the nose cone of a rocket fired vertically. To make sure the delicate instruments survive the launch, your task is to determine the acceleration of the rocket before it uses up its fuel. The rocket is launched straight up with a constant acceleration until the fuel is gone 30 seconds later. To collect enough data, the total flight time must be 5.0 minutes before the rocket crashes to the ground.
4. Because parents are concerned that children are learning “wrong” science from TV, you have been asked to be a technical advisor for a new science fiction show. The show takes place on a space station at rest in deep space far away from any stars. In the plot, a vicious criminal (Alicia Badax) escapes from the space station prison. Alicia steals a small space ship and blasts off to meet her partners somewhere in deep space. If she is to just barely escape, how long do her partners have to transport her off her ship before she is destroyed by a photon torpedo from the space station? In the story, the stolen ship accelerates in a straight line at its maximum possible acceleration of 30 m/sec2. After 10 minutes (600 seconds) all of the fuel is burned and the ship coasts at a constant velocity. Meanwhile, the hero of this episode (Major Starr) learns of the escape while dining with the station’s commander. Of course she immediately rushes off to fire photon torpedoes at Alicia. Once fired, a photon torpedo travels at a constant velocity of 20,000 m/s. By that time Alicia has a 30 minute (1800 seconds) head start on the photon torpedo.

Why was it necessary to find a “boring’ area to make the Hubble Deep Field?

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19. Why was it necessary to find a “boring’ area to make the Hubble Deep Field?
20. How far away are most of the distant galaxies in this image?
21. What problems do solar wind particles create in making these images and how are the problems resolved?
22. How many images in how many colored filters were used to make the Deep Field?
Go to https://media.dcccd.edu/video.php?vid=6795 and watch the video called Looking Deep. Answer the questions:
D. Go to https://media.dcccd.edu/video.php?vid=6796 and watch the video called Hubble’s Extreme Deep Field Sees Farther Back In Time. Answer the following questions:
23. Why is taking a look deep into the universe like taking a trip down memory lane?
24. What year was Hubble’s Ultra Deep Field taken?
25. What extra wavelength of light, beyond the visible, was used to create the Hubble’s Extreme Deep Field?

11. Was the Big Bang accompanied by a giant flash of light?

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11. Was the Big Bang accompanied by a giant flash of light?
12. Why is the Cosmic Microwave Background also called the universe’s baby picture?
13. What was the age of the universe when the Cosmic Microwave Background emerged?
14. What kind of temperature variations does the Cosmic Microwave Background show?
15. If the universe was dense and hot when it was first formed, why was it dark?
16. Did stars exist when the Cosmic Microwave Background photon escaped?
17. What is reionization?
18. What is the name of the new telescope that will succeed the Hubble Space Telescope?
Go to https://media.dcccd.edu/video.php?vid=6786 and watch the video called The Great Photon Escape. Answer the questions:

A 5600 kg mass car is taking a turn at 72 m/s. If the frictional force here is 44,000N, what is the radius of curvature of the turn?

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A 5600 kg mass car is taking a turn at 72 m/s. If the frictional force here is 44,000N, what is the radius of curvature of the turn?
Up where the ISS (International Space Station) orbits at 387 km, even though they are weightless there still is an acceleration due to gravity. Calculate its value and what it is in respect to 8g at the Earth’s surface.
Going back to the previous question, how long does it take the ISS to orbit? (You must calculate this and not just look it up!)
If a person on a 35.0 m diameter Ferris wheel feels 30% heavier at the bottom of the wheel, how fast is it going around?
A large box with mass 45 kg is being pushed up a ramp at a 32o incline at a constant velocity by a man pushing parallel to the incline for 7.80 m. If the coefficient of kinetic friction is 0.25, what is:
The force the man is pushing on the box.
The work done by the man on the box.
The force of friction.
The work done by the friction force.
A spring with negligible mass is suspended next to a ruler such that the end of the spring at equilibrium is at the 0 cm mark on the ruler. If a 3.0 kg mass is suspended from the spring and it stretches so that the end of the spring is at the 17 cm mark, what is the spring constant k?
A softball having a mass of 0.45 kg is pitched horizontally at spring with spring constant 78 N/m. If the ball hits the spring and compresses it 56 cm, how fast was the softball moving initially?
A roller coaster is a height of 120 m and has a series of dips. What is he velocity at the bottom (assuming this is 120 m below the top) and what is the velocity at a bump that is 75 m above the ground?
Please show all work