angular/circular motion by mr Lamek.pptx

Motion in circular path

1. TOPIC 1 ANGURAL MOTION

2. ANGULAR MOTION By definition. This is the motion of a body or object in circular form (rotating form). Example rotation of wheel of the bicycle. Angular motion can be describe Based on the angle swept by the Line joining a point and rotating Object.

3. Parameters of angular motion Angular motion it is characterized by parameters such as. Angular displacement ( θ ) Angular velocity ( ω ) Angular acceleration ( α ) 1: Angular displacement ( θ ) Is the change in the angular position of the object in rotational motion. The rotation of the object always in certain angle θ which is now give us the angular displacement.

4. Formular of calculating angular displacement Consider the figure below.

5. 2: Angular velocity ( ω ) By definition. Is the rate of change of angular displacement of the rotating object or body. SI unity of angular velocity is ω . It SI unit rad/ There fore. The average angular velocity can be given as or w = NOTE. Angular velocity sometimes referred to as the angular frequence and is given in terms of frequence of revolution ‘ f’  

6. Tangential velocity, Vt Is the phenomenon where the object moves in rotational motion at constant speed , constant changing in direction of motion. It SI unit m/  

7. Relation between tangential velocity and angular velocity Consider the figure below.

8. 3: angular acceleration ( α ) Is the ratio of the change of the average angular velocity to the time interval. Its SI unit is rad/  

9. Relation between the tangential acceleration ( ɑ t ) and the angular acceleration ( α )

10. CIRCULAR MOTION When the body move in a circular path at constant or variable velocity is called circular motion Example 1. The rotation of the moon around the earth 2. the cyclist moving around a curved path

11. Parameters of circular motion Centripetal acceleration Centripetal force Centrifugal force 1:Centripetal acceleration Is the acceleration toward the center of the circle. Centripetal means that toward the center. but

12. 2: Centripetal force Is the force that is directed toward the center of circle This is based on the second newtons law of motion.

13. 3: CENTRIFUGAL FORCE

14. TORQUE

15. IMPORTANT CONCEPT We know that But F= ma and a= rα Then , torque =m α But m = moment of inertia TORQUE = I α MOMENT OF INERTIA Is the sum of product of mass of the object and square of its radius (distance). Its denoted by letter I I= Its SI unit is kg  

16. Moment of inertia of some bodies For a sphere for a disc I= (2/5) I= (1/2) For ring for a slender rod I= I= (1/12)  

17. Work done by torque

18. Application of torque in daily life Opening a bottle of cap using a opener. Opening the door using doorknob Engaging a gear while driving a car Opening the wheel nut using spanner

19. THANK YOU