The current is defined as the amount of charge Q that passes through a given point of a wire in a time

:

Since I=500 A and the time interval is

the charge is

One electron has a charge of

, therefore the number of electrons that pass a point in the wire during 4 minutes is

electrons
Answer:
An elliptical orbit is the revolving of one object around another in an oval-shaped path called an ellipse. The planets in the solar system orbit the sun in elliptical orbits. Many satellites orbit the Earth in elliptical orbits as does the moon.
If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.
20 J/s = 10% of Supply
20 J/s = (0.1) x (Supply)
Divide each side by 0.1:
Supply = (20 J/s) / (0.1)
<em>Supply = 200 J/s </em>(200 watts)
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Here's something to think about: What could you do to make the lamp more efficient ? Answer: Use it for a heater !
If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about. Suddenly ... bada-boom ... the lamp is 90% efficient !
Answer:
Explanation:
Given
mass of saturated liquid water 
at
specific volume is
(From Table A-4,Saturated water Temperature table)



Final Volume 


Specific volume at this stage



Now we see the value and find the temperature it corresponds to specific volume at vapor stage in the table.



Answer:
There is some sort of "rollers" on the trail part that is used to make the roller coaster move when it is going up. Then because of that, the speed gets quicker when it drops down, so then it could move for a longer time until it reaches the next arch.
Explanation:
hope this helps :)