What is the pressure at the bottom
of a 2.50 m deep pool of water?

126423.413

Explanation:

assuming you want absolute P

P = P_atm + rho g h

look up density of water (rho) in kg/m^3

then apply the numbers

I get 126423.413

f is prop to m1xm2 double m1 double force

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me