moments, levers, gears

what is a rotation caused by?

when a force is applied on one side of a pivot

how is a moment defined?

the turning effect of a force about a pivot

what is the unit for moment?

Nm (capitalised like this)

what is the equation for moment?

force x distance

not given in exam

what is the distance that you use when calculating moment?

the perpendicular from the line of action of the force to the pivot

how can you increase moment?

by applying pressure further from the pivot, or increasing force

what is the principle of moments?

if an object is balanced, the total clockwise moment equals the total anticlockwise moment about that pivot

what is the purpose of a lever?

a lever is a force multiplier

it increase the size of a force to make an object rotate more easily

how can you make a lever work better?

increase size of force

increase distance of force applied from pivot

what does a gear do?

multiplies the effector of a turning force using moments

what do gears consist of?

wheels with toothed edges that rotates on an axle/shaft (which is the pivot)

how do gears work?

the teeth of gears slot into the teeth of another. when one gear turns, the other turns - one turns anticlockwise, one clockwise

the size of the gear will change the distance of teeth to pivot, so the moment changes from one gear to the next, but the work done is the same