BAB 5

Bab 5
Circular Motion

Hello readers!!!!!

Before discussing this topic, do you still remember about circumference???? I hope yo won't forget it. Because we're going to use this circumference material for this topic. So, what is circumference?

Circumference is can be said as perimeter of the circle to determine the length from a point of a circle to this point in the circle. if we want to determine that, don't forget this formula....

s = 2πR

1) Uniform Circular Motion 

    Uniform Circular motion is the motion of an object traveling at a constant speed of a circular motion. 

    priod is the time requuired to travel once around the circle to make one revolution. 

      

       V = 2πR / T    

    If expressed in units of radiian, one complete circle covers an angle of Ө = 2π radians. Therefore, the angular velocity of the object making a uniforom circular motion is 

ω= Ө/T = 2π / T

     * ω = angular velocity 

we get a relationship between speed and angular velocity in a circular motion as : 

V = ωR

Before we start to the next, these are the notes that we also have to know. 

     

1 rpm = 2πrad/60 rad/s

2) Centripetal acceleration 

     Magnitude ac of the centripetal acceleration on the speed v of the object and the radius r of the circular path. 

Ac = V^2 / R

3) Applications 

•      Safe Driving 

             

μs ---- dry : 0.9 

μs ---- icy : 0.1 

V = √μgr

μ = friction 

For the safe riding, the velocity must be lower than √μgr. 

• Satellites in circular orbit

    

G = universal gravitation

    = 6.67 x 10^-11 N m^2/k^2