Students will use the scientific process to explore the effects of force on an object in motion.
For each group:
Newton’s first law of motion describes the tendency of all objects and matter in the universe is to stay still, or if moving, to continue moving in the same direction, unless acted on by some outside force. The teaching of force and motion in third grade sets the foundation for further understanding when its principles are revisited again in sixth and seventh grades, and with a more in-depth focus in eighth grade.
This lesson plan uses a pendulum, as when a pendulum is set in motion it remains in motion, thus allowing time to perform experiments on an object in motion. Many universities exhibit large pendulums that actually show the rotation of the earth, hence they are important instruments having to do with force and motion.
This activity requires students to practice a basic scientific process. A question is given to them and they make predictions before setting up an experiment to prove or disprove their prediction. Students record their results and analyze their findings.
1. Use Science Process and Thinking Skills
2. Manifest Scientific Attitudes and Interests
3. Understand Science Concepts and Principles
4. Communicate Effectively Using Science Language and Reasoning
Invitation to Learn
What happens when force is applied to an object in motion? Two similar activities compare the effects of a gentle force and a harder force on an object in motion.
Explain that students will be building a machine to help further explore the effects of force on an object in motion. Each group is responsible for building a machine and using it to experiment with applying force to an object in motion.
Students observe forces in nature. Compare the effects of a strong wind and a light breeze on a shrub or tree. Observe cars going by their house. If they live near an intersection, watch and compare the force necessary for the car to slow down to turn. Do cars traveling at higher speeds have to brake sooner and harder than cars traveling slower? What else did they discover that changed its motion as a result of being acted on by a force? Report findings to the class.
Have students record results on the Rock-A-Bye Pendulum worksheet and discuss. Include an explanation of the effects of various forces on objects in motion in their science journals. They will articulate, demonstrate, or draw.
King, Kenneth. (2005). Making Sense of Motion. Science Scope. p. 22-26.
"Making Sense of Motion" begins with a general statement that interest in motion comes at an early age as exhibited by a very young child playing with a car and making the vrooomm sounds that suggest speed. All students need to develop an understanding of motion and force. Activities including hands-on investigation involve use of higher order thinking skills.