Models and Designs Model a representation of how

Models and Designs

• Model – a representation of how something works or is built. • Black box – any system that cannot be directly observed or understood. • Collaboration - scientists (and people) do this when they share possible solutions to a problem.

• Consensus – a group of scientists (or people) come to an agreement on something is called. • Circuit – an unbroken pathway along which electricity travels. • Switch – connects (opens) or disconnects (closes) the pathway that electricity is traveling along.

• Conceptual model – a model formed in the mind, can be drawn, or two-dimensional. • Physical model – a model which is a 3 dimensional representation of something. • Examples of models – – Solar system - Doll - Match-box car

Siphon’s work through two forces (gravity and cohesion – hydrogen bonds of water) (water goes from higher to lower areas and “pulls” the water behind it) In order for a siphon to work: 1. The siphon tube must be full of water (no air bubbles). 2. One end must be at the bottom of the container of liquid. 3. The 2 nd end of the tube must be below the first end of the tube. (this is using gravity)

Go-cart word bank • Axle – a rod that connects to and turns the wheels (in our case a wooden stick). • Bearing – the surface that something spins or turns on (the loop of the binder clip in most cases) • Friction- the resistance to movement on surfaces that touch (wheels on floor). • Hub – the center of the wheel that is fastened to the axle.

• Traction – a kind of friction that allows wheels to turn without slipping on the surface. • Wheel – the disk that turns on a central axis. • CAD – Computer Assisted Design – helps engineers know what something looks like and how it works without having to build it. • Inertia – a resistance to a change in position (it keeps an object doing what it is doing – like sitting still)

• Momentum – inertia in motion – something that has momentum wants to keep going. • Velocity – speed in a certain direction. • Speed – distance over time (such as miles per hour – in our case meters per second) • Variable – anything that can change the way something works

• Design – a drawing of how something should look or work (the way it is put together). • System – two or more objects (parts) work together to make something work. • Technology – the using of science to develop objects, machines, and materials that are used to make our lives better. • Engineer - a person who uses scientific knowledge to design useful things.

5 steps of engineering • • • Design Build Test Modify (change) Re-test