Answer:
The molecules in a solid are all packed together and vibrating.
The molecules in a liquid are able to fit into a space, because they aren't packed together, they are more apart from each other.
The molecules in a gas are even further apart from each other, and able to move way more freely.
Explanation:
Solid things are solid because of the molecules being so packed together.
Liquid things are liquid because of there being not as many in one space, it's more spread out.
Gas things are gas because of the molecules moving fast and there aren't as many so it's more spread out than other things.
I hope this helped!
All of them are examples of energy being transferred by waves<span />
Answer:
a) 4.9W b) 3.82W
Explanation:
Stefan-Boltzmann law of radiation formulae:
Q/t (W) = sigma* e*A*T^4
Sigma = 5.67*10^-8 j/sm^2K^4 (Stefano Boltzmann constant)
e = emissivity
T = absolute temperature in kelvin and A = area in m^2
a) Q/t = 140/10000(m^2) * 0.87* 5.67* 10^-8* (290^4) = 4.9W
b) without hair the
Q/t = 140/ 10000(m^2) *0.68* 5.67* 10^-8* (290^4)
= 3.82W
Answer:
Q = 675 [J]
Explanation:
We can calculate the amount of heat transfer by means of the following expression that includes the mass and temperature change in a body as a function of the specific heat.
where:
m = mass = 25 [gr]
Cp = specific heat = 0.9 [J/g*°C]
Tinitial = 55 [°C]
Tfinal = 25 [°C]
![Q=25*0.9*(55-25)\\Q=675 [J]](https://tex.z-dn.net/?f=Q%3D25%2A0.9%2A%2855-25%29%5C%5CQ%3D675%20%5BJ%5D)
