1. Rotational Motion and Torque Chapter 7 and 8 Physics

2. -When an object spins it is said to undergo rotational motion. (motion of a body as it spins around an axis of rotation) -Rotational motion is described in terms of the angle through which a point moves around the circle.

3. -Angles measured in radians  360 o = 2 radians ------- 1 radian is approximately 57 o 1 radian = 57.2957 degrees 1 degree = 0.0174532 radians

4. -Angular displacement - the angle through which a point, line, or body is rotated in a specific direction and around a specific axisAngular displacement

5. -Angular speed (ω)– the rate at which a body rotates about an axis (radians per second)

6. Torque – a quantity that measures the ability of a force to rotate an object around some axisTorque Lever arm – perpendicular distance from the axis of rotation to a line drawn along the direction of force

7. Torque = force x lever arm x angle of rotation = Fd(sinθ) = torque F = force d = distance from applied force to axis of rotation θ = angle of rotation

8. Example – Trying to open a door by pushing or pulling at the handle vs. trying to open the door by pushing or pulling beside the hinge. Which is harder? ** More torque is produced with a longer lever arm. ** When doing work, you want to maximize torque by making the lever arm as long as possible, thus making the rotation easier. Long wrench vs. short wrench. - Torque will be positive or negative based on the direction of rotation

9. Yea, Homework! Chapter 7 - Review problems Pages 269-273 #1, 2, 3, 4, 26, 27, 29, 30, 31, 32, 33 Chapter 8 – Review problems Pages 305-309 #1, 2, 3, 7, 8, 12