Usage:

1. The block sits on an inclined plane: Click the circle near the right edge and drag the mouse up/down to change the angle of inclination theta

2. Red Arrow represents the gravitational force. ( which has two green force components). Click near the tip of the red arrow and drag the mouse up/down to change the mass of the block. ( mg)

3. Yellow arrow is the normal force Fn

Under which conditions the normal force becomes zero (vanish)?

4. Click the up-right corner of the block to apply external force F on that block.

(Drag the mouse to change the vector F, if the mouse is within the circle the force F=0.

5. Click again at the tip of the F vector and drag the mouse button to change the direction of the force F only.

When will we have a maximum net force?

6. The normal force were determined from external force F and the gravitational force mg. Then we will know the friction between the block and the incline plane.

7. The blue arrow is the friction force. Notice: there is a maximum value.

8. All the force are added together to find the net force NF. ( the black arrow)

9. You can change different value of coefficient of static friction from the selection.