Atoms
Cells
Trees
Flowers
Rocks
Animals
Humans
Chemicals
Gas
Water
-causes heat; if it's not used correctly, it can cause injury
-when falling, the friction between your knee/leg and the ground can cause scrapes
!!HOPE THIS HELPS!!
Answer:
J = 2.044x10⁶ A/m²
v = 1.50x10⁻⁴ m/s
Explanation:
The current density (J) of the copper wire is giving by:
<em>where I: electric current and A: cross-sectional area of the copper wire</em>
<u>The cross-sectional area of the copper wire can be calculated by:</u>
<u>Substituting the calculated area in the equation (1) we have:</u>
Hence, the current density is 2.044x10⁶ A/m².
To find the drift speed (v), we need to use the next equation:
<em>where n: the free-electron density, q: module of the charge of the electron </em>
So, the drift speed is 1.50x10⁻⁴ m/s.
Have a nice day!
Answer:
<em>To reverse the direction of an electric current, we simply reverse the voltage either automatically with the help of some switching circuitry or manually by changing the voltage source terminals connection. </em>
Explanation:
For electric current to flow, there must be a potential difference, usually referred to as the voltage. The electric current flow is analogous to the flow of water under the action of a pump, through a series of pipe connections. The voltage is similar to the driving action of the pump, and current flows the same way water flows. The resistance due to drag on the pipe wall is equivalent to electric resistance. For current to flow in the reverse direction, the voltage or rather, the potential difference is changed, causing the current to flow in the opposite direction. This can be done by switching the terminals of the voltage source, or by automatic means. The automatic switching can be done with a transistor based circuitry.
Given:
Water, 2 kilograms
T1 = 20 degrees Celsius, T2 = 100
degrees Celsius.
Required:
Heat produced
Solution:
Q (heat) = nRT = nR(T2 = T1)
Q (heat) = 2 kilograms (4.184 kiloJoules
per kilogram Celsius) (100 degrees Celsius – 20 degrees Celsius)
<u>Q (heat) = 669.42 Joules
</u>This is the amount of heat
produced in boiling 2 kg of water.
