How a Toy Stores and Transfers Mechanical Energy?
What You Need to Know
Energy is the ability an object has to do work. Work is the product of force times the distance. It moves an object in the direction of that force. Mechanical energy is the total kinetic and potential energy of an object. Kinetic energy is the energy an object has because of its motion. Potential energy is the energy an object has because of its position, also called stored energy. Energy transfer is the change of one form of energy to another.
How Does Energy Do Work?
An object with mechanical energy is able to do work. An object's mechanical energy enables it to apply a force to another object causing it to move. The amount of force applied times the distance the object moves equals the amount of work done on the object. In the process of doing work, the object doing the work transfers mechanical energy to the object upon which work is done.
The toy in the diagram on page 124 is an example of how mechanical energy of an object can do work. When the spring is compressed, it possesses mechanical energy in the form of potential energy. When the compressed spring separates, the potential energy in the spring is changed to kinetic energy, and the toy moves as in figure B.
What Does This Have to Do with Building a Toy That Will Throw a Ball toward a Target?
Your toy must be able to store and transfer energy in some way so that it can throw a ball in a certain direction. You can start the toy by squeezing a spring together or stretching a rubber band, for example, but it must be the toy that throws the ball. It cannot be your energy that directly moves the ball.
The energy in the sunlight that reaches Earth's surface every hour is enough to meet world energy demand for an entire year. The problem is finding ways to store and transfer this solar energy so that it may be used for other purposes.
Oil is used to produce fuels, which are forms of potential energy. Fuel in a car is burned, changing it into different forms of energy that make the car move. When gasoline is burned, it produces gases that pollute the air. Scientists are exploring alternative energy sources. Hybrid cars are examples of machines that use alternative energy sources. The energy sources for these cars are gasoline and electricity. The electricity is stored in a rechargeable battery, which recharges as the car is driven.
Now, start experimenting with toys that store and transfer energy.
- Research the motion of different kinds of simple machines, such as wheels and gears.
- Study the motion of toys. Determine the type of simple machines involved.
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