1. CHAPTER 5.3
Force and Motion in Two
Dimensions

2. FORCE AND MOTION IN TWO
DIMENSIONS
 How do I analyze motion on an incline plane?

3. INCLINED PLANE


4. INCLINED PLANE
 Implications?

5. INCLINED PLANE
 Motion is along the plane, so we will tilt our incline plane

6. INCLINED PLANE
 Gravity always pulls straight down
 We want to sum our forces in the x and y direction
 What do we do with Fg?

7. INCLINED PLANE


8. EXAMPLE
 If a box of mass 25 kg is sitting on an incline that is 33º above
horizontal, what are the components of weight parallel and
perpendicular to the incline?

9. EXAMPLE
 A mass of 5.0 kg is on an inclined plane. If the component of
weight parallel to the surface is 19 N, what is the angle of the
incline?

10. INCLINE PLANE
 What about friction and the normal force?
 Sum the forces in the x direction?
 Sum of the forces in the y direction?

11. HOMEWORK
 Page 133
 # 33 – 35

12. EXAMPLE
 A string exerts a force of 18 N on a box at an angle of 34º from
the horizontal. What is the horizontal component of the force on
the box?

13. EXAMPLE
 From Quiz:
 What is the weight?
45º 30º

14. EXAMPLE


15. EXAMPLE
 A 62 kg person on skis on going down a hill sloped at 37º. The
coefficient of kinetic friction between the skis and the snow is
0.15. How fast is the skier going 5.0 s after starting from rest?

16. HOMEWORK
 Page 133
 # 36 – 38