|Name of Activity||Bicycle Unit: Engineering the Wheel|
|Keywords||bikes, force, friction, rolling, ramp, travel, wheel, tire, LEGO|
|Grade Level||4, 5, 6|
|Time||1 Hour Total|
|Brief Description||Using bikes as an example, students will examine the force of friction. They will apply their knowledge to build an object that rolls down a ramp and travels as far as possible.|
|Lesson Objectives:||- To experiment with wheel sizes, shapes, and materials.
- To learn about the affect of friction on bike tire design.
- To practice teamwork and competition.
|Materials Needed:||- Ramp (made of wood, cardboard, foamcore etc.) that is approximately 25 cm high at the top.
- Tape lines to mark where to start measuring distance.
- ‘Ramp Roller Challenge’ and ‘Tire Chart’ Worksheets.
- Homemade LEGO kits (consisting of different types of wheels, axles, bushings, beams, bricks and weighted bricks).
- Other materials that cars could be constructed out of:
– Wood, cardboard, straws, old containers, art supplies, blocks, etc.
|Preparation and Set Up:||- Create kits to make cars with.
- Make a ramp that is about 25 cm high and mark starting point on ramp and start point for measuring distance at the bottom of the ramp.
- Photocopy a ‘Tire Chart’ worksheet for each student.
- Photocopy a ‘Ramp Roller Challenge’ Worksheet for each student.
- Arrange students in pairs.
- Distribute materials.
|Necessary Background||Wheels must respond to a lot of forces. Riders weight, Bumps and dips, Weight of the frame, Wheel itself.
Friction is a force that affects the wheels of a bike because tires are the part of the bike in contact with the road. Friction is the force that appears when two things rub together (rub your hands – makes heat). The smoother two objects sliding against each other are, the less friction there is. Microscopic ridges are what interact with each other when any two objects meet. If a wheel had no friction it would not be able to move a bike; it would just spin in one place. However, too much friction causes a rolling wheel to slow down, and makes it harder to pedal.