# Uniform Circular Motion and Centrifugal Force

Khaled Marashdeh
Physics and Robotics teacher
Dhahran Ahliyya Schools
Dharhan, Saudi Arabia

Saudi Aramco and produced
by Sultan Bin Abdel Aziz
Science & Technology Center

The objective of this video lesson is to correct the misconception in the students’ understanding of centrifugal force. The lesson will work to clarify this misconception by using Newton's three laws of motion, particularly the law of inertia, and will demonstrate that the only force acting during a uniform circular motion is centripetal force (i.e., towards the center)  - not including the force of gravity. The lesson will involve experiments and activities that enable students to explore and investigate by themselves the fact that centrifugal force does not exist and to confirm that it is just a centripetal force. Students will learn to calculate the centripetal force for an object in a uniform circular motion. Before starting this lesson, students should be familiar with the following:

• Force analysis of any static or moving object or drawing the Free Body Diagram.
• Newton's three laws of motion.
• Knowledge of the following terms: Inertia, uniform circular  motion, acceleration, tangent of a circle, the circumference and the formula to calculate it (2πr), weight and the law to calculate it (w = mg).
• Knowledge of the following symbols for the scientific terms and its measurement units in English language: Force (F) unit (Newton, N), mass (m) unit (kilogram Kg), velocity (v) unit (m / s), radius (r) unit (meter m), time (t) (seconds) the number of cycles (n). Using the value of the acceleration of gravity as (9.8 m/s2) without approximation.

Khaled Marashdeh is a Jordanian teacher working in Saudi Arabia and he has been a teacher for 17 years.  His university major was Physics with a minor in Computer Science, and he also has a degree in Education. He is working to use LEGO educational products in his teaching of physics and is pleased to have been chosen as one of three correspondents worldwide for the Robotics Competition First LEGO League (FLL). Please visit the FLL Blog.

This site, sponsored by the Regents Prep Center, provides animations of centripetal force.
http://regentsprep.org/regents/physics/phys06/bcentrif/default.htm

This site, provided by The Physics Classroom, presents a discussion and animation on centripetal force.
http://www.physicsclassroom.com/mmedia/circmot/cf.cfm

This site, also provided by The Physics Classroom, presents a comprehensive discussion on the topic of “Motion Characteristics for Circular Motion”.
http://www.physicsclassroom.com/class/circles/U6L1c.cfm

This site, sponsored by Physics Lessons, presents an animation model of a carousel to demonstrate the characteristics of Centripetal Force.
http://www.physicslessons.com/phe/carousel.htm

#### Hello We are glad that you

March 13, 2012 at 7:58 pm

Hello

We are glad that you like this lesson. Under the "Transcript" menu item above, you will find the complete transcript in both English and in Arabic. I hope this will help. Also, you can Download the video lesson via the "Download" menu item above. Let us know if you have problems.

#### I like this a lot Jazaka

March 13, 2012 at 2:36 pm

I like this a lot Jazaka Allahu KhairIs there anyway to be able to daolnowd these lessons to my Windows Media Player so to be able to listen to it over and over again during the day at work without being online?(don't have internet at home)Do you have the Transliteration available for the Arabic script?Also, it would be helpful if I could print the lessons and have a hardcopy for review, making notes, etc

#### Good Luck Khaled :)

February 20, 2012 at 10:24 am

Good Luck Khaled :)

#### So great

February 17, 2012 at 5:21 am

So great

#### Hello We are glad that you

March 13, 2012 at 7:58 pm

Hello

We are glad that you like this lesson. Under the "Transcript" menu item above, you will find the complete transcript in both English and in Arabic. I hope this will help. Also, you can Download the video lesson via the "Download" menu item above. Let us know if you have problems.

#### I like this a lot Jazaka

March 13, 2012 at 2:36 pm

I like this a lot Jazaka Allahu KhairIs there anyway to be able to daolnowd these lessons to my Windows Media Player so to be able to listen to it over and over again during the day at work without being online?(don't have internet at home)Do you have the Transliteration available for the Arabic script?Also, it would be helpful if I could print the lessons and have a hardcopy for review, making notes, etc

#### Good Luck Khaled :)

February 20, 2012 at 10:24 am

Good Luck Khaled :)

#### So great

February 17, 2012 at 5:21 am

So great