How does water pressure change with depth?

How does water pressure change with depth?

• A. The pressure is independent of depth
• B. The deeper the water, the greater the pressure
• C. Pressure decreases with depth
• D. Pressure fluctuates randomly with depth

Answer: (B)

Water pressure comes from the weight of the water above a point. In a resting column, more water above a deeper point means more force per unit area pushing down, so pressure increases with depth. The pressure at depth h is roughly Psurface + ρ g h, where Psurface is the surface pressure (usually atmospheric), ρ is the water’s density, and g is gravity. Because ρ and g are nearly constant for water, pressure climbs roughly linearly as you go deeper. For example, about 10 meters of water adds around 1 atmosphere of pressure, so deeper depths mean higher pressure.

Water pressure comes from the weight of the water above a point. In a resting column, more water above a deeper point means more force per unit area pushing down, so pressure increases with depth. The pressure at depth h is roughly Psurface + ρ g h, where Psurface is the surface pressure (usually atmospheric), ρ is the water’s density, and g is gravity. Because ρ and g are nearly constant for water, pressure climbs roughly linearly as you go deeper. For example, about 10 meters of water adds around 1 atmosphere of pressure, so deeper depths mean higher pressure.