Answer:
therefore critical angle c= 69.79°
Explanation:
Canola oil is less dense than water, so it floats over water.
Given 
which is higher than that of water
refractive index of water 
to calculate critical angle of light going from the oil into water
we know that

now putting values we get

c= 
c=69.79°
therefore critical angle c= 69.79°
Answer:
a) The final pressure is 1.68 atm.
b) The work done by the gas is 305.3 J.
Explanation:
a) The final pressure of an isothermal expansion is given by:

Where:
: is the initial pressure = 5.79 atm
: is the final pressure =?
: is the initial volume = 420 cm³
: is the final volume = 1450 cm³
n: is the number of moles of the gas
R: is the gas constant
Hence, the final pressure is 1.68 atm.
b) The work done by the isothermal expansion is:

Therefore, the work done by the gas is 305.3 J.
I hope it helps you!
Answer:25000/23 N/M^2
Explanation:
P=f/A=30/(0.23×0.12)=25000/23