Investigation # 1 – Using One Pulley
Part A – Using a Fixed Pulley
Purpose:
To determine if using a fixed pulley to lift a load requires less force
than lifting the load using just your muscles.
Hypothesis:
Materials:




Pulley
String
Spring scale
Load (a heavy book)
 Ruler
 Metre stick
 2 chairs
Procedure: Follow steps 1-6 on p. 8 of the “Pulleys and Gears” resource
Observations:
How much force was needed to lift the load straight up using just your arm?
How much force was needed to lift the load straight up with the fixed pulley?
With a fixed pulley, does it take less force to lift the load with the pulley than
without it?
With a fixed pulley, how is the direction of the force needed to lift the load
different than with no pulley?
Conclusion:
Investigation # 1 – Using One Pulley
Part B– Using a Movable Pulley
Purpose:
To determine if using a movable pulley to lift a load requires less
force than lifting the load with a fixed pulley.
Hypothesis:
Materials:




Pulley
String
Spring scale
Load (a heavy book)
 Ruler
 Metre stick
 2 chairs
Procedure: Follow steps 1-4 on pp. 8-9 of the “Pulleys and Gears” resource.
Observations:
How much force was needed to lift the load straight up using the movable pulley?
In what direction did you apply the force when you lifted the load using the
movable pulley?
Conclusion:
Does a movable pulley reduce the amount of force needed to lift a load? Explain
why or why not.
On your blog:
Find a picture of a movable pulley, and post it to your blog. Underneath the
photo, explain how a movable pulley works, and why less force is needed to lift a
load with a movable pulley.
Categorize your post “Science” , tag it “pulleys”