Find the hydrostatic pressure on one side of the plate submerged in water (p = 1.00 8/mL) shown in the image below (all dimensions are in meters). %3D

I need these three parts answered, if you are unable to answer all three parts please leave it for another tutor to answer, thank you.

An electric hot water heater consumes 3.1 kilowatts of electricity and converts it to heat. How long will it take the water heater to heat a 67 gallon tank of water from 10 degrees Celsius to 50 degrees Celsius? (1 kilogram of water is 0.37 gallons, 1 Calorie = 4200 J).  It may be helpful to refer back to the weekly handout for guidance on this problem. Your final answer should be in minutes (rounded to the nearest 10 minutes).

A sharp knife can cut because the pressure increases when a) the surface of contact is small b) the surface of contact is large c) when we apply a large force on it regardless of the surface of contact d) both the surface of contact and the force are large