# Rotational Motion Angular Measure (radian) Angular Speed and velocity

## Presentation on theme: "Rotational Motion Angular Measure (radian) Angular Speed and velocity"— Presentation transcript:

Rotational Motion Angular Measure (radian) Angular Speed and velocity
Centripetal Acceleration Centripetal Force Angular Acceleration

Angular measure y x=r cos(q) r y y=r sin(q) q x x

Angular measure s Q= r r s 2p radians = 360° 1.0 radian = 57.3°
y 1.0 radian = 57.3° s Q= radians r r s q x x

How far to the moon? Early Greek scientists estimated that the earth’s diameter is 3.5 times larger than the moon’s. If a penny covers up the moon when held 200 cm from your eye, How far is the moon from Earth? (the diameter of a penny is 1.9 cm)

Small angles h≈ s & r ≈ x r s h q x h/r ≈ s/r ≈ h/x Sin q ≈ q ≈ tan q

Angular speed and velocity
Average angular speed

Linear speed and angular speed
h q x

Linear speed and angular speed
h q x h/r ≈ s/r ≈ h/x Sin q ≈ q ≈ tan q

Angular acceleration

Angular acceleration

Circular Motion (with constant a)

Circular Motion (constant a)

Kinetic Energy

d

Torque

a=? T=?

T=? St = Ia TR = 1/2MR2 (a/R) a=? T= 1/2M a mg-T=ma mg- 1/2M a=ma
mg= (1/2M +m)a mg (1/2M +m) T= 1/2M a SF=ma mg-T=ma a =

Work and Power

Similar presentations