PSHS 3rd Year Physics Batch 2013 Circular Motion Terms in kinematics Uniform Circular Motion Non uniform Circular Motion Rotational Motion Force (Centripetal & Tangential) Acceleratio (Centripetal & Tangential)

1. PHYSICSPSHS 3RD YEAR Session 5

2. TUTORIAL REMINDERS 2 Hours today Be ready with your: Sci. calculator Physics notes Session 4 handout Paper Pen Today’s Flow: CIRCULAR MOTION 1.) Review of terms 2.) PinoyHenyo 3.) Self-check exercises 4.) Challenge exercises

3. Answers: Terms 1.Directed radially toward the center CENTRIPETAL 2. Constant speed along a straight line UNIFORM VELOCITY 3. Angular displacement divided by time t ANGULAR VELOCITY

4. Answers: Terms 4.The direction of the linear velocity of an object in circular motion TANGENTIAL 5. Movement of an object in a circle experiencing uniform speed UNIFORM CIRCULAR MOTION 6. Directed distance (distance where direction is important) DISPLACEMENT

5. Answers: Terms 7.What is done to curved roads to reduce skidding BANKING 8. What an object experiences when there is a change in the magnitude of its velocity (speed), or a change in its direction of motion ACCELERATION

6. Circular Motion

7. Does an object in uniform circular motion have constant velocity? No. Constant speed but constant changing direction of motion. Thus, velocity is NOT constant.

10. EX.4 (page 111, Giancoli) A 0.150-kg ball on the end of a 1.10m-long cord (negligible mass) is swung in a VERTICAL CIRCLE. Determine the minimum speed the ball must have at the top of its arc so that the ball continues moving in a circle.

11. What’s the difference? TANGENTIAL FORCE Ftan Acts to INCREASE or DECREASE the speed of the object CENTRIPETAL FORCE FR Keeps object moving in a CIRCLE

12. Non-Uniform Circular Motion TANGENTIAL acceleration – the direction of the tangential acceleration is in the direction of the change in velocity

13. Non-Uniform Circular Motion Total vector acceleration a Magnitude of total vector a Direction of total vector a Resultant vector of aR and atan

14. A race car starts from rest in the pit area and accelerates at a uniform rate to a speed of 35 m/s in 11 sec, moving on a circular track of radius 500m. Assuming constant tangential acc’n, find a.) Tangential acc’nb.) Radial acc’n, at the instant when the speed v is 15 m/s.

15. Law of Universal Gravitation (Adapted from Page 119, Giancoli) Tyrone and Mia have masses of 50 kg and 75 kg respectively. They sit 1.0 m apart in the front center of their Physics class. Estimate the magnitude of the gravitational force each exerts on the other.

16. ROTATIONAL MOTION

17. Rotational Motion All points in the object move in circles. The centers of these circles all lie in a line called the axis of rotation. Where