How do simple machines change the direction of force?

Question

Leo Abeyta · Accepted Answer

Simple machines use a pivot point to modify the magnitude and/or direction of a force.

Forces are vector quantities so they combine as vectors.

Simple machines use a pivot point such as a lever fulcrum or axle bearing to provide a "counteractive" force to combine with the applied force(s) to produce a resultant force, acting in a different direction and/or with a different magnitude to that applied.

The forces must comply with the rules of Newtonian physics,

#F=ma#
i.e. if the forces are not in balance then something will be accelerating.

#W = F*d#
work = force * distance (= energy)

#power = "energy / time" #, etc.

For a lever in balance #F_1*L_1= F_2*L_2# :

Note that there must be a counteractive force acting upwards at the fulcrum if the lever is in balance

Gears, wheels and pulleys use the same principles but allow continuous movement, whereas a lever has a limited range of movement.

Leo Abeyta · Answer

undefined Simple machines change the direction of force by redirecting the applied force over a longer distance or through a different angle, thereby achieving the desired result. This redirection of force is accomplished through the use of mechanisms such as levers, pulleys, inclined planes, wedges, screws, and wheels and axles. Each type of simple machine operates based on fundamental principles of physics, such as the conservation of energy and the principle of mechanical advantage, to alter the direction or magnitude of applied forces in order to perform work more efficiently.