Well, we know that the total energy in a closed system remains constant.
The problem with the story of Eva is that she is not in a closed system.
If the dark room were really a closed system, then she could press the
button or turn the switch all day, and the lamp could not light. It needs
electrical energy coming in from somewhere in order to turn on.
Let's say that Eva used her arm muscles to strike a match and light the
candle on the table. Then we would have have food energy, muscle
energy, chemical energy in the match, chemical energy in the candle,
heat and light energy coming out of the candle, heat energy soaking into
her hand, light energy bouncing off of the book and into her eyes ... all
going on during the story, and the sum total of all of them would remain
constant.
Power = Work / Time
If W = 50 J and T = 5s
P = W/T = 50J/5s = 10 Watts
The correct answer is:
<span>A. electron attraction between electron and nucleus = centripetal force of the orbiting electron
In fact, Bohr model depicts the atom as a nucleus surrounded by electrons in circular orbit around it, similar to the planets around the Sun. The centripetal force that keeps the electrons in circular motion around the nucles is provided by the electrostatic force between the electrons and the nucleus, so option A is the correct one.</span>
Answer:
Average speed = 0.35 m/s
Explanation:
Given the following data;
Distance = 1.3 Km
Time = 62 minutes
To find the average speed in m/s;
First of all, we would convert the quantities to their standard unit (S.I) of measurement;
Conversion:
1.3 kilometres to meters = 1.3 * 1000 = 1300 meters
For time;
1 minute = 60 seconds
62 minutes = X
Cross-multiplying, we have;
X = 62 * 60
X = 3720 seconds
Now, we can calculate the average speed in m/s using the formula;


Average speed = 0.35 m/s
Answer:
b . Move the conductor near a magnet