It’s burning wax. All of the other options are physical changes .
Answer:<span>Humid air is lighter, so it has lower pressure.
The reason is the molecules of water are H2O, whose molar mass is 18 g/mol.
These molecules displaces molecules of N2 and O2, whose molar masses are:
N2: 2*14g/mol = 28 g/mol, and
O2: 2*16g/mol = 32 g/mol.
Then molecules of 28g/mol and 32 g/mol are being replaced with molecules of 18g/mol, leading to a lower weight of the same volume of air, which results in lower pressure.
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Explanation:
We will calculate the gravitational potential energy as follows.
= 
= 1164000 J
or, = 1164 kJ (as 1 kJ = 1000 J)
Now, we will calculate the change in potential energy as follows.
= 
= 
= -873000 J
or, = -873 kJ
Thus, we can conclude that change in gravitational potential energy is -873 kJ.
I think its the last one, a student slips on the ice in front of school and sprains his ankle. An example of a natural fiber could be cotton B.
Answer:
= 2 beats per seconds
Explanation:
- From |f -f'| = modulus of the difference between the frequency given.
- Difference between the frequency will give us the number of beat per seconds.
These also shows how to get the period of the tuning forks.
