1. The Inclined Plane q
Components of Fg

2. 90o - q q Fg

3. 90o - q q
Fg y q Fg
Fg x

4. Fg y Fg Fg x 90o - q q q Fn friction The block will slide if…
Fgx exceeds max static friction
Fg x

5. Example
Determine the acceleration of a kg hovercraft if it is placed on a plank inclined at 10o. Assume there is no friction.
10o

6. Example 2
Determine the size of a horizontal force needed to keep the kg hovercraft stationary on the plank inclined at 10o. Assume there is no friction.
10o

7. Study Problem # 38 page 119
The solution is posted to Schoolwires

8. Example Problem
A 2.00 kg book rests on a level plank. The plank is gradually tilted more and more by one student while a second student measures the angle of the incline. The students notice the book starts sliding when the plank reaches an angle of 35.0o. Additionally, through the use of Logger Pro, they determine the book accelerates down the slope at 1.00 m/s/s. Explain these observations qualitatively

9. Example Problem
A 2.00 kg book rests on a level plank. The plank is gradually tilted more and more by one student while a second student measures the angle of the incline. The students notice the book does not slide at 35.0o , but starts sliding when the plank reaches an angle of 35.1o. Additionally, through the use of Logger Pro, they determine the book accelerates down the slope at 1.00 m/s/s. Determine ms and mk

10. Friction and the Inclined Plane
A plank is tilted until a block on the plank starts to slide. Once it starts to slide, it accelerates down the slope, UNLESS the angle is reduced by 5 ⁰ - 10⁰, in which case, the block will slide at a constant velocity. Why? Construct an FBD and explain these events.

11. Determine ms
A block of wood is placed on a board. The board is gradually tilted more and more. Which of the forces on the block change as the angle is increased?
By taking one measurement, one can determine the coefficient of static friction. Use a protractor to determine ms for the wood block on the brown side of the whiteboard.
Test your results by calculating how much force should be required to get the block sliding across the level board if 1.0kg was on the block.