1. Horizontal Circular Motion

2. Recap of Centripetal Acceleration
Because the speed of an object displaying circular motion is constant and tangential, circular motion produces a centripetal acceleration (acceleration directed toward the center of the circular path.)

3. Recap of Centripetal Force
Since acceleration is toward the center, so is the force that is produced from that acceleration
This force is not always a separate force but can be made up of several forces. It is best to think of it as the net force required to hold the object on its circular path

5. Horizontal Circular Motion
Frictional forces between the ground and objects allow “turns” to be made. That means that the net force as you round a corner is friction.

6. Example 1:
Determine the maximum speed at which a kg truck can round a curve that has a radius of 20.0m, if the coefficient of friction between the tires and the road is 0.58.

7. Example 2
1. A car has a mass of 1400 kg and is going around a corner that has a radius of 100 m, the coefficient of friction between the car and the road is What is the maximum force the car have going around the corner without sliding off the road?
i. Force due to friction

8. ii. Find the maximum speed the car can go without sliding off the curve.
Centripetal force must be less than 8927 N

9. Centrifugal Force
the outwards force is sometimes referred to as centrifugal force
since centrifugal force is an imaginary force, nothing causes it
centrifugal force only exists because of Newton’s 3rd Law

10. Newton’s 3rd Law
When you are pulling on the rope inward the ball is pulling on your hand outward
Force A on B = - Force B on A

11. Misconceptions about Centripetal Force
it is mistakenly thought that centripetal force pulls outward away from the centre of a circle
so why when you swing a ball on the end of a rope does the ball pull outward away from your hand?
Think:
what causes the ball to continue moving in a circular path?
What happens when you let go of the rope?

12. Eg) A centrifuge that simulates increased gravity rotates at 2800 rpm
Eg) A centrifuge that simulates increased gravity rotates at 2800 rpm. The measure of the radius of the spinning drum is 2.5 cm. Determine centripetal acceleration.

13. Space stations are circular and rotate to generate an acceleration due to gravity equal to centripetal acceleration of 9.81m/s2
Assignment: WS1 #1-6 WS2 #1-3