Results

Outcomes

In this unit you will learn about:

• The concept of elasticity
• Understand the relationship between tension and extension

In this lesson you will learn about:

• The concept of elasticity
• Understand the relationship between tension and extension

You have learnt about static electricity where charged particles (electrons) can move from one object into another giving objects an overall charge. In this unit1 you will learn about current electricity. This is when a continuous flow of charge can be created using a circuit made of conducting wires and an energy source.

The flicker of numbers on a handheld calculator, nerve impulses carrying signals of vision to the brain, an ultrasound device sending a signal to a computer screen, the brain sending a message for a baby to twitch its toes, an electric train pulling into a station, a hydroelectric plant sending energy to metropolitan and rural users—these and many other examples of electricity involve electric current, which is the movement of charge. Humanity has harnessed electricity, the basis of this technology, to improve our quality of life. 

There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation.

When two objects interacting through a field change relative position, the energy stored in the field is changed.

• Explain the Conservation of Mechanical Energy concept using kinetic energy (KE) and gravitational potential energy (PE).
• Describe how the Energy Bar and Pie Charts relate to position and speed.
• Explain how changing the Skater Mass affects energy.
• Explain how changing the Track Friction affects energy.
• Predict position or estimate speed from Energy Bar and Pie Charts.
• Calculate speed or height at one position from information about a different position.
• Calculate KE and PE at one position from information about a different position.
• Design a skate park using the concepts of mechanical energy and energy conservation.

A force diagram is a useful tool to help us visualise forces acting on an object and gives us informa- tion about the object’s motion. We often use force diagrams when solving calculations involving the forces acting on an object.

By the end of this lesson you will be able to:

1. Define and explain what a force is
2. List and describe the main kinds of forces
3. Explain the effects of a force

• Predict, qualitatively, how an external force will affect the speed and direction of an object's motion.
• Explain the effects with the help of a free body diagram.
• Use free body diagrams to draw position, velocity, acceleration and force graphs and vice versa.
• Explain how the graphs relate to one another.
• Given a scenario or a graph, sketch all four graphs.