LINES OF INQUIRY
1. The different types of forces (Form) 2. How forces are used in machines (Function) 3. The process of designing a machine to make life easier (Causation)
SEARCH TIPS:
Britannica: search for "simple machines".
World Book: search for "machines", "force". "gravity".
Britannica and World Book can READ it to you.
Brain Pop Jnr: search "forces" (see "inclined plane", "levers", "acceleration", "work". "forces".