Answer:
Power=720[watt]
Explanation:
We need to remember the definition of mechanical work which is equal to the product of the force applied by the distance traveled.
In this problem, we have to find the power which is defined as the work divided into the time in which such work is performed. This way if we have the displacement and the time, this will be the speed with which this work is done.
![Power= W/T\\T=time [s]\\W=work [J]\\Power = F*V\\where\\V=velocity [m/s]\\Power=1800 * 0.4 = 720 [watt]](https://tex.z-dn.net/?f=Power%3D%20W%2FT%5C%5CT%3Dtime%20%5Bs%5D%5C%5CW%3Dwork%20%5BJ%5D%5C%5CPower%20%3D%20F%2AV%5C%5Cwhere%5C%5CV%3Dvelocity%20%5Bm%2Fs%5D%5C%5CPower%3D1800%20%2A%200.4%20%3D%20720%20%5Bwatt%5D)
Answer:
Options A and D are correct
Explanation:
The thermal conductivity of a metal is the property of a metal to allow heat flow through it. conductivity is higher in conductors and low in insulators. Thermal conductivity is high in metals due to the metallic bonds that exist in metals and the presence of free electrons within the metal which allow easy flow of heat from one atom to another.From the problem the rod which contains freer electrons will allow more heat to flow easily hence have a higher thermal conductivity.
Thermal conductivity has the formula below;

- k is thermal conductivity,
- A is cross sectional area
- Q is quantity of heat transferred to material.
- ΔT is temperature change.
From the above equation we can see that thermal conductivity is inversely proportional to A and directly proportional to L. This mean the rod with less area will have a higher thermal conductivity and the rod with a higher length will have higher k. Hence option C i wrong and option D is correct.
For specific heat, its very much different from thermal conductivity. Specific heat is the ability of a material to hold heat while thermal conductivity is the ability of heat to flow through a material.
fusion is when solid changes it's state to liquid
and vaporization is when liquid changes it's state to gas
so the difference between fusion and vaporization is the state
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