lift: to bring upward
www.webmd.com
energy: the ability to do work
www.supercoloring.com
simple machine: a device with few or
no moving parts
www.fi.edu
pulley: a grooved wheel with a rope
around it
www.wisegeek.com
groove: a cut in the surface
www.wisegeek.com
machine: a device that makes work
easier
www.freepik.com
en.clipart-fr.com