PULLEY
PULLEY: A pulley is a simple machine made with a rope, belt or chain
wrapped around a grooved wheel. A pulley works two ways. It can change the
direction of a force or it can change the amount of force. A fixed pulley
changes the direction of the applied force. ( Ex. Raising the flag ) . A
movable pulley is attached to the object you are moving.
ACTIVITY: What happens when you increase the number of
pulleys?
Materials:
three students
two broom handles
one ten foot long piece of twine or rope
1. Have one student tie the end of the twine onto one of the broom handles.
2. Have two of the students stand about two and one half feet apart so that
the broom handles are
held about two feet apart.
3. Wrap the twine around the broom handles twice.
4. Have the third student pull on the twine as the other two students try
to hold the broom handles
apart.
5. Now wrap the twine around the broom handles two more times and repeat
step 4.
To WORK
IS SIMPLE WITH SIMPLE MACHINES