Two glass containers, A and B, are placed on a lab bench. The containers are connected at their bottoms by a tube with a closed tap. The first diagram shows the water levels in the two containers. 
The density of water is 1000 kg/m31000 \text{ kg/m}^31000 kg/m3.
State the equation linking pressure difference, height, density, and gravitational field strength (ggg).
Calculate the pressure that the water exerts at the base of container A when the tap is closed. (Assume g=10 N/kgg = 10 \text{ N/kg}g=10 N/kg or 9.8 N/kg9.8 \text{ N/kg}9.8 N/kg).
The tap is now opened. Water flows through the tube for some time until it stops. Describe how the final water level in container B compares to the final water level in container A.
Explain why the water starts to flow and why it eventually stops flowing.
