Back to: Jss2 Basic Science (BST)
Topic: Energy Transfer
One of the most important ideas about energy is that it can’t be made or broken down, but it can be changed from one form to another. In the lessons before this one, we talked briefly about the different kinds of energy. To help you remember, they are mechanical energy, light energy, sound energy, electrical energy, heat energy, nuclear energy, magnetic energy, chemical energy, and solar energy. All of these kinds of energy are very important to our daily lives.
In a mechanical system, work is the movement of energy from one place to another. There are many different kinds of energy, but they all have one thing in common: when they change from one form to another, the amount stays the same. If you let an object with mass m fall freely to the ground from a resting point, At that point, all of the energy is in the form of potential energy, or mgh. As the object fell, it picked up speed, or kinetic energy. Potential energy goes down and kinetic energy goes up. When the motion is over, when the object hits the ground, all of the energy is kinetic. The object has the same amount of kinetic energy as the initial potential energy. Between its highest point and the ground, it has both kinetic energy and potential energy.
In a motorcycle, the kinetic energy of the fuel is made from the chemical potential energy of the fuel. When a force is applied to a wheelbarrow that is at rest, the wheelbarrow moves, and this movement is called kinetic energy. But what gave the wheelbarrow its movement? It came from the person pushing the wheelbarrow, who moved it by using the chemical energy stored in the food they ate. In other words, when the person worked on the wheelbarrow, they gave some of the chemical energy they had stored in themselves to the wheelbarrow. This gave the wheelbarrow more kinetic energy. Because of this, the person has less chemical energy, and the wheelbarrow has more kinetic energy. When you kick a football, this is another example. When you move your legs and feet, the chemical energy in the food you ate turns into mechanical energy. When you kick the ball with your foot, you give it kinetic energy. This makes the ball movement for a while before it stops.
At a wind farm, the moving air’s kinetic energy can be used to move the blades of a turbine. The energy makes it possible for the air particles to exert a force and move the blades. As the blades turn, their energy is converted into electricity. This electricity is then sent to homes and businesses so that electrical appliances can run. Also, an electric bulb turns electricity from the mains into light that can be seen and heat that can be felt.