What is Mechanical Kinetic Energy?
What is Kinetic Energy?
Students need to be familiar with the classifications of energy to be able to use them in science classes and in life. Kinetic energy is one such classification. The other is potential energy. This lesson plan focuses on kinetic energy. Potential energy will be discussed in the lesson plan following this one. Be creative when explaining these concepts to students. For example, use the activity below to introduce your students to the classification of kinetic energy.
For this activity, you will need a small disposable tub and a small knife.
- Fill the plastic tub with water.
- Ask students to place their hands under the water as you slowly pour it out from the top of the tub. Students should feel a small amount of pressure from the water pouring over their hands.
- Poke a minute hole in the bottom of the tub.
- Covering the hole with your finger, fill the tub with water.
- Remove you finger from the hole and ask the same students to place their hands under the water to feel the pressure of the water coming out of the small hole. The students should notice a great increase in pressure as compared to the first time they placed their hands under the water.
- Discuss the difference in levels of pressure felt when the water was being poured out each time.
- Explain to students that this is energy in use. To measure this energy, called kinetic energy, we use the kinetic energy formula.
Explain to students that kinetic energy is the energy an object has because it is in motion. Discuss various examples of kinetic energy with your students.
Using the Kinetic Energy Formula
Explain to your students that the kinetic energy formula is kinetic energy= 1/2 x mass x (velocity x velocity). Refer students to the Kinetic Energy Formula Study Guide to reaffirm what you have told them about the kinetic energy formula. Discuss how the kinetic energy formula is used in the world around us by taking a look at the following example.
How is the kinetic energy formula used in building dams?
The idea of a dam is to use the motion of the water and change that energy into stored energy that we can use as a power source. Therefore, the stronger we can make the force of the water, the more energy we can change to stored energy. Imagine the dam as if it were a showerhead. If you removed the shower head, the pressure would not be as great. Using that same concept, if you turn your shower head so that the smallest available holes are used, you will increase the pressure of your water flow.However, you aren't trying to convert that energy. In that case of a dam, the kinetic energy formula is used not just to increase the pressure of the water, but so that architects know how thick to build the dam so that it can actually hold the pressure and not be destroyed by it.
To help students develop more interest in kinetic energy, ask them where they think the kinetic energy formula would be useful in other areas. Ask students to come up with various examples. Follow this lesson plan up with the Potential Energy Lesson Plan that follows it.