Solution :
Given data :
Mass of ice, m = 200 g
Mass of water, M = 500 g
Temperature of ice = 0°C
Temperature of water = 20°C
We known ;
The latent heat of fusion of water is
The specific heat of water, C = 4.18 kJ/kg K
a). Heat required to change the ice into water is :
J
Heat required to cool the warm water is :
From above result,
This means that total ice could not melt.
So, the temperature must be T = 0°C
b). Q' = mL
m = 0.1253 kg
m = 125.3 g
m = 125 g
Therefore, 125 g of ice had melted.
Planets are not hot enough, and that's because they lack the internal energy sources that stars have: thermonuclear fusion (They do emit a little light, mainly infrared light, but nothing compared to the sun)
Planets don't have their own light, so simply they do not emit light, this phenomena goes back to their information. When they are formed, they are much, much less hotter than the stars. In stars, fusion reaction always goes on, in which energy, as well as light is formed, so, there is light for stars to emit for a long time.
Answer:
By using the formula
Z.t= average number of events
=10/100 ×1
=0.1hertz