what is a device that makes work easier by changing the size or direction of force?
3 examples of machines
wheelchairs chopsticks and scissors
what common machine is a screwdriver that is used to pry off the lid on a paint can?
the work you do on a machine is called?
the work done by a machine on an object is called?
when a screwdriver is used to open a can, both the size and direction of the _______ force change
a ramp will decrease the size of input force ( your force) needed to lift a box and _________ the distance over which the force is exerted
when a machine changes the size of the force the ________ through which the force is exerted must also change.
what is the number of times a machine multiplies force called?
MA= output force / input force
a machine that has a mechanical advantage of greater than 1 has an output force that is
greater than the input force
a machine that has a mechanical advantage of less than 1 reduces the output force but can increase the _____________ an object moves.
what is the quantity that measures the ratio of work output to work input called?
mechanical efficiency = work output / work input x 100
when a machine drills holes in metal, some of the work input is used to overcome _____________ between the metal and drill
machine that is 100 % efficient
why is it impossible to build an ideal machine
every machine has moving parts
what do some machines use to lower friction between moving parts?
lubricants ; oil & grease
machines make work seem less by multiplying forces or changing the direction of force,
work input = ?
no machine can what?
can put out more energy than put into ( cant make energy.)