Answer:
a) v = 4.4 m/s
b) F = 400 N
Explanation:
a) ½kx² = ½mv²
v = √(kx²/m)
F = kx
v = √(Fx/m)
v = √(800(0.012) / 0.5) = √19.2 = 4.3817...
b) Fd = ½mv²
F = mv²/2d
F = 0.5(19.2) / (2(0.012) = 400 N
None whatsoever.
You're confusing the formation of the Earth with the so-called "Big Bang".
The sun and planets formed billions of years AFTER the Big Bang.
1) 5765 mol
First of all, we need to find the volume of the gas, which corresponds to the volume of the room:

Now we can fidn the number of moles of the gas by using the ideal gas equation:

where
is the gas pressure
is the gas volume
n is the number of moles
R is the gas constant
is the gas temperature
Solving for n,

2) 184 kg
The mass of one mole is equal to the molar mass of the oxygen:

so if we have n moles, the mass of the n moles will be given by

since n = 5765 mol, we find

By measuring the expansion of the substance. In that case you use a thermometer