science chapter 3 Flashcards
the transfer of energy that occurs when a force is applied over a distance
work
forces that don’t make object move have no __________.
work
calculation for work
f l d
the rate at which work is done
power
calculation for power
p l t
any device that makes doing something easier
machine
the force originally applied before a machine changes it
input force
the product of the input force after being put into a machine
output force
the ratio of a machine’s output force produced to the input force applied
mechanical advantage
calculation for mechanical advantage
in l out
the mechanical advantage if no friction existed
ideal mechanical advantage
do work using only one movement
simple machines
a simple machine made up of a bar that pivots, or rotates, about a fixed point.
lever
the point about which a lever pivots
fulcrum
first class lever
soda tab
in(down) out(up)
—————————-
f
second class lever
wheelbarrow
in(up) out(up)
——————————
f
third class lever
tweezers
in(up) out(up)
—————————————-
f
calculation for mechanical advantage of levers
MA = input L / Output L
distinguishes different types of levers
fulcrum
an axle attached to the center of a wheel and both rotate together (like a screwdriver)
wheel and axle
calculation of ideal mechanical advantage of wheel and axle
radius wheel / radius axle
a flat, sloped surface (like a ramp)
inclined plane
Ideal Mechanical advantage of Inclined Planes
length / height
a sloped surface that moves
wedge
an inclined plane wrapped around a cylinder
screw
a simple machine that is a grooved wheel with a rope and cable wrapped around it
pulley
two or more simple machines that operate together (can opener)
compound machine
wheel and axle with teeth around the wheel
gears
wedge MA
length / width
pulley MA
of strings in system (not including one u pull)
