A swimming pool measures 10m by 7m by 2m calculate the full force exerted by the water against the bottom. What is the pressure at the bottom due to the water?

Answer 1

water is about 1000 kg/m^3
we have 140 m^3 of water
so 140,000 kg of water
the force of gravity on that is
9.81 * 140,000 = 1,373,400
Newton's third law says the bottom of the pool has to push up with that same force 1,373,400 Newtons

pressure = force/area
= 1,373,400/(10*7) = 19,620 Newtons/m^2 or Pascals

By the way, that is pressure above atmospheric or "gage" pressure. For absolute pressure you need to add one atmosphere to that or about 100,000 Pascals. This is not normally done because the atmosphere also pushes up from underneath.