1. Explain, using Kinetic theory, why when you have a hot room, the room cools down when you open a window to the cold outside.
Answer:
According to kinetic theory of gases, at higher temperature, the molecules in air have higher kinetic energy and they are moving at a faster speed. Hence the pressure is greater. And Air moves from higher pressure to lower pressure.
In a hot room, the air pressure is greater. The cool air outside has lower pressure. On opening the window, Air moves from higher pressure to lower pressure, from outside to inside.
2. If an atom is 1*10^(-10) m wide, and the nucleus is 1*10^(-15) m wide, how wide would the atom be if the nucleus was scaled up to be 1 cm wide?
Answer:
When nucleus was scaled upto 1 cm, atom would be 10^(5) cm.
The question is pretty simple, we just have to scale the size of nucleus to larger value and get the size of atom accordingly.
We know that
when nucleus is 10^(-15) m => atom is 10^(-10) m
When nucleus becomes 1 m => atom is 10^(-10) * 10^(15) m = 10^(5) m
When nucleus is 1 * 10^(-2) => atom is 10^(5) * 10^(-2) m
When nucleus is 1 cm => atom is 10^(5) cm