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Experience:  Bachelors Degree and CPA with Accounting work experience
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# 1. A machine is supplied energy at a rate of 4,000 W and

### Customer Question

1.   A machine is supplied energy at a rate of 4,000 W and does useful work at a rate of 3,760 W. What is the efficiency of the machine?

A. 96 percent
B. 92 percent
C. 97 percent
D. 94 percent

2.   If the velocity of an object changes from 65 m/s to 98 m/s during a time interval of 12 s, what is the acceleration of the object?

A. 13.58 m/s
B. 5.42 m/s
C. 33 m/s
D. 2.75 m/s

3.   How much time should be allowed for a 605-mile car trip if the car will be traveling at an average speed of 55 miles per hour?

A. 10.5 hours
B. 8.75 hours
C. 9 hours
D. 11 hours

4.   A tank with a flat bottom is filled with water to a height of 4 meters. What is the pressure at any point at the bottom of the tank? (You can ignore atmospheric pressure when calculating your answer.)

A. 39.2 kPa
B. 18.9 kPa
C. 4.0 kPa
D. 9.8 kPa

6.   What is the kinetic energy of an object that has a mass of 30 kilograms and moves with a velocity of 20 m/s?

A. 5,880 J
B. 6,000 J
C. 12,000 J
D. 2,940 J

6.   What is the kinetic energy of an object that has a mass of 30 kilograms and moves with a velocity of 20 m/s?

A. 5,880 J
B. 6,000 J
C. 12,000 J
D. 2,940 J

7.   Heat from burning fuel warms the walls of the firebox section of the furnace in

A. a hot-air heating system.
B. a compressor compartment.
C. a hot-water heating system.
D. an evaporation system.

9.   During the stage of internal combustion engine operation in which the piston rises and compresses the fuel in the combustion chamber,

A. both the intake and exhaust valves are closed.
B. the exhaust valve is open and the intake valve is closed.
C. both the intake and exhaust valves are open.
D. the intake valve is open and the exhaust valve is closed.

10.   A temperature of 200°F is equivalent to approximately

A. 840°C.
B. 232°C.
C. 37.8°C.
D. 93.3°C.

11.   Which one of the following substances is a liquid fuel used in rocket engines?

A. Potassium perchlorate
B. Liquid oxygen
C. Codium nitrate
D. Ammonia

12.   Liquid alcohol will change to vapor when its temperature reaches the

A. boiling point.
B. melting point.
C. freezing point.
D. fusing point.

13.   Rarefaction occurs only in a _______ wave.

A. forced.
B. sympathetic.
C. transverse.
D. longitudinal.
Submitted: 5 years ago.
Category: Homework
Expert:  Bizhelp replied 5 years ago.

You need to spend \$3 to view this post. Add Funds to your account and buy credits.
Customer: replied 5 years ago.
Expert:  Bizhelp replied 5 years ago.
I'm completely sure. Note, you have question #6 listed twice.
Customer: replied 5 years ago.
K thanks heading into class gonna turn in my work in a few,

Do u by chance know these quickly I posted them but know one has responded ?

14.   In a transverse wave that travels through a medium, the molecules of the medium vibrate

A. at twice the velocity of the molecules in a longitudinal wave.
B. at right angles to the direction in which the wave travels.
C. with smaller amplitudes than the molecules in a longitudinal wave.
D. in the direction in which the wave travels.

15.   An overtone that's a whole number multiple of the fundamental frequency of a string is called a

A. discordant sound.
B. pitch.
C. harmonic.
D. scale.

16.   A surface receiving sound is moved from its original position to a position three times farther away from the source of the sound. The intensity of the received sound thus becomes

A. three times as high.
B. nine times as low.
C. nine times as high.
D. three times as low.

17.   In a stringed musical instrument, the sound frequency of a particular string can be increased by

A. lengthening the string.
B. increasing the string's thickness.
C. tightening the string.
D. loosening the string.

18.   When a tuning fork vibrates over an open pipe and the air in the pipe starts to vibrate, the vibrations in the tube are caused by

A. reinforcement.
B. resonance.
C. beats.
D. harmonics.

19.   The atomic number of oxygen is 8, because oxygen has

A. an atomic mass of 8.
B. eight protons in the nucleus.
C. electrons in eight shells.
D. a second shell with eight electrons.

20.   Which of the following elements is stable?

A. Boron, atomic number 5
B. Neon, atomic number 10
C. Fluorine, atomic number 9
D. Carbon, atomic number 6

21.   Which of the following is represented in the highest percentage by volume in dry air?

A. Nitrogen
B. Hydrogen
C. Carbon dioxide
D. Oxygen

22.   The measure of the number of atoms in one element that will combine with an atom of another element is

A. molecular number.
B. valence.
C. atomic number.
D. atomic charge.

23.   A chemical reaction in which compounds break up into simpler constituents is a _______ reaction.

A. double replacement
B. combination
C. substitution
D. decomposition

24.   The valence of aluminum is +3, and the valence of chlorine is –1. The formula for aluminum chloride is correctly written as

A. AlCl3.
B. ClAl3.
C. Al3Cl.
D. Cl3Al.

25.   A material that transmits nearly all the light in a ray because it offers little resistance to the light is

A. transparent.
B. fluorescent.
C. translucent.
D. opaque.

26.   A virtual image produced by a lens is always

A. located in front of the lens.
B. smaller than the object.
C. larger than the object.
D. located in the back of the lens.

27.   A magnifying glass is an example of a _______ lens.

A. double-concave
B. converging
C. plano-concave
D. plano-convex

28.   Which of the following frequencies falls in the range of RF waves used by commercial radio broadcasting stations?

A. 6,000 Hz
B. 6,000,000 Hz
C. 600,000 Hz
D. 60 Hz

29.   When all parts of a circuit are composed of conducting materials, the circuit is said to be

A. shorted.
B. open.
C. closed.
D. parallel.

30.   Electrons are emitted from a conductor when the conductor is

A. subjected to a small voltage.
B. cooled rapidly.
C. bombarded by high-speed electrons.
D. exposed to weak light.

Expert:  Bizhelp replied 5 years ago.
It looks like someone is working on these on your other post. I think it would take me at least an hour to do these. If this is OK, please close your other post and let me know.

Thanks.

Customer: replied 5 years ago.
Oh ok I c well I hope the other dude hurrys , cause this is makeup work for only getting a 65 on
Last turn in papers ,. But thx for all your help
Expert:  Bizhelp replied 5 years ago.