Pulleys
Screen 1 image
Pulleys
help
us
lift
things
 
that
are
heavy.
 
A
pulley
uses
 
a
wheel
 
and
 
a
rope,
 
cord,
or
chain.
 
Pulleys
make
 
it
easier
 
to
lift
heavy
things.
 
A
rock
climber
wears
 
a
harness.
 
It
is
attached
to
 
a
person
with
 
a
pulley.
 
This
helps
keep
 
the
climber
from
falling
 
if
he or she
slips.