MECHANICS 2

1. MECHANICS 2 Rotational Motion

2. Teaching Ideas • Outside – object rotating about a fixed position (line of students link arms, one end stays fixed and the rest sweep around in a circle) • Can you keep the line straight? • Mix up where you are in the line to experience the rotation from a different position • Is it easier to rotate about the person in the centre of the line?

3. Difference between Rotational motion and circular motion

4. New vocab! • What are the 3 typical ways we can describe the LINEAR motion of an object? Acceleration Velocity Displacement

5. Rotational motion words θ d = displacement(m) θ= angular displacement (rad) v = velocity (ms-1) ω= angular velocity (rads-1) v = ∆d= ∆θ ∆t ∆t a = acceleration (ms-2) α= angular acceleration (rads-2) a=∆vα=∆ω ∆t ∆t

6. d d=r Relationship between distance and angular displacement when θ in radians θ v=r a=rα

7. Teaching Idea • Re-write equations of motion with the new terminology for rotational motion • Build up the four EoM using the jigsaw pieces • Replace the three (/four) variables with our new variables

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