[tex]dane:\\m = 300 \ g = 0,3 \ kg\\S = 15 \ cm\times 25 \ cm = 0,15 \ m\times0,25 \ m = 0,0375 \ m^{2}}\\g = 10\frac{N}{kg}\\szukane:\\p = ?\\\\\\p=\frac{F}{S}\\\\ale \ \ F = m\cdot g = 0,3 \ kg\cdot10\frac{N}{kg} = 3 \ N\\\\p = \frac{3 \ N}{0,0375 \ m^{2}}\\\\\underline{p = 80\frac{N}{m^{2}} = 80 \ Pa}[/tex]
Odp. Szukane ciśnienie p = 80 Pa.
