Circular Motion Lab
In this activity students use a circular motion "machine" (made of a stopper, pen casing, string, and weights) to investigate the variables that affect circular motion. The students then graph their data in order to find mathematical relationships between the variables they have studied.
Context for Use
Resource Type: Activities:Lab Activity
Grade Level: High School (9-12)
Description and Teaching Materials
o Class discussion about the variables influencing circular motion
-A force which pulls an object toward the center of a circle is called a ___________ force.
-How much centripetal force needs to be exerted to cause an object to move in a circle?
-The amount of centripetal force that you need to exert depends on:
- 1. the mass of the object you are whirling - heavier objects require more force,
- 2. how fast you are whirling it - going faster requires more force,
- 3. the radius of the circle.
o Students quick write about the first three lab questions, then share with a partner and revise.
-1. State Newton's first law of motion.
-2. The diagram on the right shows an overhead view of an object moving clockwise in a circular motion. The object is released at point P. Draw the subsequent motion of the body.
-3. What are the two things which must be constant for an object to have a constant velocity?
o Class discussion about the first three questions followed by a demonstration of lab procedure.
o Assign groups and have the class answer questions 4-6 as a group.
o Discuss the answer for questions 4-6 and release students to start the lab.
o Monitor student progress throughout the lab and assist groups that need additional help.
o Assist each group as they apply a best fit line to their graph.
o Students write the equation for their graph and describe the relationship it shows between variables. Student Handout for Circular Motion lab (Microsoft Word 136kB Aug3 09) Smart Board for Circular Motion Concepts ( 707kB Aug3 09)
Teaching Notes and Tips
- Finding the correct fit line for the graphs from lab data will also require some teacher guidance especially if you have not worked with your students on using excel for anything other than linear relationships.