[tex]dane:\\m = 64 \ g = 0,064 \ kg\\a = 4 \ cm = 0,04 \ m\\S = a^{2} = 0,04 \ m\times 0,04 \ m = 0,0016 \ m^{2}\\g = 10\frac{N}{kg}\\szukane:\\p = ?\\\\Rozwiazanie\\\\p = \frac{F}{S}\\\\F = m\cdot g = 0,064 \ kg\cdot10\frac{N}{kg} = 0,64 \ N\\\\p = \frac{0,64 \ N}{0,0016 \ m^{2}} = 400 \ Pa[/tex]
