Answer:0.0704 kg
Explanation:
Given
initial Absolute pressure
=210+101.325=311.325
as the volume remains constant therefore
therefore Gauge pressure is 337.44-101.325=236.117 KPa
Initial mass 
Final mass 
Therefore 
=0.91-0.839=0.0704 kg of air needs to be removed to get initial pressure back
Answer:
i)20369 photons
ii) 40 ps
Explanation:
Momentum of one Sodium atom:
In other to stop it, it must absorb the same momentum in photons:
Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:
The force of gravity between two objects is:
F = G*m1*m2/r^2
So, it is dependent of the two masses and the distance between their centers of mass.
Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.
