To Non-Java ALLSTAR Network Website

                                                                                                                                                                        JAVA-capable browser required for graphic-based menus (Exploer 3.0 or Netscape 2.0 or greater)

Please let me remind all of you--this material is copyrighted.  Though partially funded by NASA, it is still a private site.  Therefore, before using our materials in any form, electronic or otherwise, you need to ask permission.
There are two ways to browse the site: (1) use the search button above to find specific materials using keywords; or,
(2) go to specific headings like history, principles or careers at specific levels above and click on the button.
Teachers may go directly to the Teachers' Guide from the For Teachers button above or site browse as in (1) and (2).

FAQnewred.gif (906 bytes)           

Multiplication of Forces

Pascal's Law states that the pressures in both cylinders are the same (p1=p2).   Thus, given a force, F1, of 10 pounds (lbs) in the right cylinder acting on a piston area, A1, of 2 square inches (sq. in.) a pressure in the right cylinder, p1, of 5 pounds per square inch (lbs/sq. in. = psi) is produced.  Now if A2 is given as 5 sq. in., then the force developed in the left cylinder is F2 = p2xA2, or 25 lbs.  This is due to the fact that p1=p2.  Thus Pascal's Law shows the way in which one can increase the output force for a given input force...regulate the areas of the pistons!

<img src="images/hydro029.gif" align="bottom" width="320" height="200">eq001.gif (1057 bytes)
Press on the arrows to see the Multiplication affect.

The only disadvantage is the size of the piston stroke involved.  Let's say, piston 2 moves (up) 10 inches.  For the previous problem the work done by piston 2 is F2 times the stroke of piston 2 (10 in. x 25 lbs).  If no losses exist in the system due to friction, then work is conserved and piston 1 must do 250 in-lb of work. Therefore, the F1 must move down 25 inches (250 in-lbs/10 lb force)! To move piston 2 up, a volume of 50 cubic inches (cu. in.) of incompressible oil must be pumped in at 5 psi (since pressure times Volume is also another way to find work). The movements of the pistons are measured relative to the bottom of the cylinder with all the measurements computed to produce 100 % efficiency.

If you don't see the animation, click here to download Macromedia Shockwave Player.


Send all comments to allstar@fiu.edu
1995-2017 ALLSTAR Network. All rights reserved worldwide.

Funded in part by

Updated: March 12, 2004