Wk. 3: Simple Machines

Week #4: Simple Machines

Objectives

• Recognize examples of simple machines encountered in everyday life
• Demonstrate how rollers can be used to move an object
• Compare the wheel and the roller
• Compare systems of pulleys for effort required to move a mass
• Explore using a lever to move different masses
• Design and construct a device that uses energy storing components (rubber bands)
• Compare designs and identify strengths and weaknesses
• Practice safety

Activities

• Learners examined wooden shapes and identified ones usable as simple machines.
• Learners set up a balance of weights on a ruler. They then modified the position of the fulcrum to balance out unequal weights.
• Learners explored how using one or more pulleys required different amounts of effort.
• Learners constructed a simple catapult based on provided examples. They then tested and modified their designs to improve its performance.

Important Questions

• What are three examples of simple machines used to help people?
• What are at least three examples of blocks from the tub that you could use as simple machines?
• When balancing the weights on the ruler, was the lighter weight closer or further away from the balancing point (fulcrum)?
• Did lifting the bucket with one pulley require more effort or less than lifting it with multiple pulleys?
• Where is the point of the most stress in your catapult? (Where does it feel like it might break when pulled back?) What would you try to make it stronger?
• What was one difficulty that you had to overcome in building your catapult?
• How does the length of the catapult arm affect how far it can throw an object? (hint: thank about distance to the fulcrum when you balanced the pucks)

Things to try at Home

• Using the hand out, identify which simple machines represented by these examples. What are six more examples of simple machines that you can find around your home?
• Many ancient civilizations used simple machines to build great monuments. Find three examples of these simple machines in use and share them in a manner of your choice that uses words and pictures (power point show, a poster, a music video, etc.).
• Build another catapult with a different design. How is this design better than your first design? Where is the fulcrum in your new design? Where is the force or effort being stored?
• Catapults and trebuchets are still being built even to this day, usually as part of an engineering challenge. Look for pictures and videos from events like Beakerhead or the Okotoks Pumpkin Chunkin and look for what designs seem to work the best.