THE RELATIONSHIP BETWEEN PRESSURE AND DEPTH

By Susan E. Butler

 

 

The purpose of this experiment is to determine the relationship between depth and pressure.

 

Pressure and depth have a directly proportional relationship. This is due to the greater column of water that pushes down on an object submersed. Conversely, as objects are lifted, and the depth decreases, pressure is reduced. This relationship between pressure and depth may be looked at with respect to the relationship between pressure and volume, as the column of water has a specific volume and corresponding to depth. Boyle’s Law describes the relationship between pressure and volume: The product of pressure and volume is a constant (PV=k). While Boyle’s Law refers to gases, it is significant to recall that both gases and liquids are fluids, and thus follow the same rules of behavior.

 

The procedure used during this experiment was to inflate a balloon at the surface of the water and measure the circumference with a measuring tape. The balloon was then taken to a 0.5000m, 1.000m, 1.500m, and 2.000m, measuring circumferences at each depth respectively.

 

 

 

Depth

 

0.000m

 

0.500m

 

1.000m

 

1.500m

 

2.00m

 

Circ (m)

 

0.320

 

0.316

 

0.292

 

0.264

 

0.247

 

 

 

0.340

 

0.328

 

0.315

 

0.284

 

0.238

 

 

 

0.335

 

0.319

 

0.306

 

0.277

 

0.251

 

 

 

0.315

 

0.300

 

0.287

 

0.264

 

0.243

 

 

The data show a direct correlation between an increase in depth and an increase in pressure. This directly proportional relationship is demonstrated by the reduction in the circumference of a balloon as it is taken to deeper depths.

 

The graph shows a linear relationship which can be mathematically expressed as y=mx+b, where y=pressure, m=slope of the line, x=depth, and b=the y intercept ( which in this case is zero).

 

In conclusion, both the data and the graphical analysis support the hypothesis statement that pressure is directly proportional to depth.

 

 

 

 

Graph Page Goes Here

 

(Circumference vs. Depth)

Swim Back to Class

Back to the Can Do Story

Back to the Beginning