Physics Independent Lab
Using the 2 mm nail, you punch a hole at the bottom side of the plastic cup. Cover the hole with the tape, making sure that it is airtight. Fill the cup with 100 ml of water. Remove the tape and record the time it takes for all the content water to flow out the hole and measure the distance the water squirt reaches. Repeat the procedure two more times, each time increasing the diameter of the hole using the 3 mm and 5 mm nails.
In a condition where gravitational force and the atmospheric pressure are disregarded and that all variables are constant, the calculation of the pressure on the water is p = f x h where p = pressure, f = force or weight of the water, h = height from the hole to the surface of the water. In this activity, the weight (f) of the water in the cup is 0. 027 g/cm3; the height is 5 cm Thus: p = f x h ? p = 0. 027 g/cm3 x 5 cm ? p = 0. 135 psi
Since a small hole allows less water to flow through it, there is only minimal movement in the liquid. This builds up the pressure in the water; therefore, the water spout shoots further because of the strong pressure that pushes it through the hole. As the hole is increased, larger amount of water escapes through it. This causes much and fast movement or turbulence on the water which makes the pressure drops, thus slowing down the velocity or the speed of the water flow.
In short, the size of the hole alters the pressure in such a way that it (the hole) causes movement on the water as fluid rushes through it. The greater the movement on the water, the lesser is the build up of pressure. Reference: Van Cleave. Janice Van Cleave’s Help! My Science Project Is Due Tomorrow! Easy Experiments You Can Do Overnight. John Wiley and Sons (2001).Sample Essay of PaperDon.com