measured pressure?

Question

measured along the surface of the water, a rectangular swimming pool has a length of 15 m. along this length, the flat bottom of the pool slopes down at an angle of 11 degrees below the horizontal, from one end to the other. by how much does the pressure at the bottom of the deep end exceed the pressure at the bottom of the shallow end?

Answer 1

the difference of depth is 15 *tg 11° =2.92m

The difference of pressure is

P = h*(mass specific of water)*g

mass specific of water = 10^3 kg/m^3 g =9.81 m/s^2

so
P = 2.92*1000*9.81 =28603pa=0.282 atmosphere