# NTNUJAVA Virtual Physics Laboratory

## JDK1.0.2 simulations (1996-2001) => Dynamics => Topic started by: Fu-Kwun Hwang on January 29, 2004, 04:31:13 pm

Title: Free-body Force Diagram
Post by: Fu-Kwun Hwang on January 29, 2004, 04:31:13 pm
In order to be successfully in applying Newton's second law to a mechanical system,
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.

Usage:
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 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.
Title: topic1
Post by: on January 30, 2004, 12:27:26 pm
Subject: help for all
Date:    Fri, 29 Jan 1999 12:53:11 +0100
From:    Jose Villasuso <villasu@arrakis.es>
To:      hwang@phy03.phy.ntnu.edu.tw
Dear Sir:FU-Kwun Hwang.

I am a High School teacher from La Corunha , Spain ( Galicia ) near
Portugal.

I realy like yours appelets of  Java  and I am used to work with them in
my classes.
If you don`t mind I would like to know if is posible for you to do one
A force pulling a block on a slope, and showing the forces growing when
you aplay diferents pulls.
Also it would be a plesure if you could do another  one: a block moving
in horizontal , changing the force angles when you pull the block, and
at the same time showing the celerity of the block. The most eficient
angle to move is when the  tg (angle) = coefficient of rubbing

Sorry for my english

I?m very pleased for having found your work, amazed work, which is very
useful for my students and also for me.
Before all, thank you very much for your work and help.

Pepe Villasuso
Title: Re: Free-body Force Diagram
Post by: bloggerics on August 04, 2010, 12:51:51 pm
well this is great effort :)
i am a UN teacher, currently psoted in indonesia and this post helps me a lot [hide]
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Title: Re: Free-body Force Diagram
Post by: lookang on August 05, 2010, 04:16:27 pm
well this is great effort :)
i am a UN teacher, currently psoted in indonesia and this post helps me a lot -*-

U can also check out http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1585.0
they are both great applets :)