http://www.ck12.org Chapter 4. Motion and Forces
FIGURE 4.55
Q: If the break-dancer lies down on the ground on his back, his weight is spread over an area of 0.75 m^2. How much
pressure does he exert on the ground in this position?
A: On his back, the pressure he exerts is:
Pressure= 0800. 75 mN 2 =1100 Pa, or 1.1 kPa
Factors That Affect Fluid Pressure
Two factors influence the pressure of fluids. They are the depth of the fluid and its density.
- A fluid exerts more pressure at greater depths. Deeper in a fluid, all of the fluid above it results in more weight
pressing down. This causes greater pressure the deeper you go. You can watch a video demonstration of depth
and fluid pressure at this URL:
http://www.youtube.com/watch?v=oUK7agBG4KA
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/82424- Denser fluids such as water exert more pressure than less dense fluids such as air. The particles of denser fluids
are closer together, so there are more collisions of particles in a given area. The difference in density of water
and air is illustrated in theFigure4.56.