Discuss with your partner.

You have seen that adjusting thread density will change the amount of effort force needed and adjusting the wheel radius will also change the amount of effort force needed.

• Explain in your own words the advantage of combining these two simple machines.

Challenge:

• Predict 3 different combinations of thread density and wheel radius which will allow the gate to be lifted using the same effort force.
• Create a Rub Goldberg device.