A glass full of water has a bottom area of 20 cm ^2 , a height of 20 cm , and a volume of 0.5 L . Assume the glass is enclosed by a jar and the air within the jar is entirely evacuated. Determine the force applied by the water on the bottom of the glass and the net vertical force exerted by the sides of the glass on the water. (Take g = 10 m/s ^2 and the density of water as 1000 kg/m ^3 )

Step-by-step solution

The given parameters are A = 20 cm ^2 = 20 10⁻⁴ m ^2 , h = 20 cm = 0.2 m , V = 0.5 L = 0.5 10⁻³ m ^3 , and = 1000 kg/m ^3 . Since the air is evacuated, the pressure at the free surface of the water is zero. The pressure at the bottom of the glass is: P = g h = 1000 10 0.2 = 2000 N/m ^2 The force applied by the water on the bottom of the glass is: F_ bottom = P A = 2000 20 10⁻⁴ = 4 N The total weight of the water in the glass is: W = V g = 1000 (0.5 10⁻³) 10 = 5 N For the water to be in equilibrium, the net vertical