1. Simple Mechanics

2. Simple machine used to amplify physical force
Simple machine used to amplify physical force. All early people used the lever in some form, for moving heaving stones or as digging sticks for land cultivation.
The principle of the lever tell us that the above is in static equilibrium, with all forces balancing, if :
F1 x D1 = F2 x D2

3. James building his own imaginary castle.

4. James try to adjust the distance between basket and the pivotal point and propel a rock over an imaginary castle.