In order to be successfully in applying Newton's second law to a mechanical
we must first be able to recognize all the forces acting on the system.
This java applet shows the free-body force diagram for a block sits on
an inclined plane.
1. a 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¡C
2. Red Arrow represents the gravitational force. ( which has two green
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 ¡C
Under which conditions the normal force becomes
4. Click the up-right corner of the block to apply external force F
(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.
Your suggestions are highly appreciated! Please click firstname.lastname@example.org
Author¡GFu-Kwun Hwang, Dept. of physics, National Taiwan Normal University
Last modified :
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