Force and SHM
Let us cosider the force exerted on a mass by a spring attached to
This force take the form F = - k X
This force law is known as Hooke's law.
This Java applet let you familar with this kind of relation and simple
How to play:
There is a spring on the table, a string is connected to the spring
over a light frictionless pulley.
You can attach mass/blocks to the spring :
The spring will relax to its equilibrium position.
Move the mouse button with the blocks
The color of those blocks above the mouse pointer will turn black.
Click the mouse button to attach those black blocks to the spring.
The mass of those attached blocks will be shown near another spring (to
You can detach mass/blocks from the spring
Press the mouse button to suspend the animation, click it again to resume.
Move the mouse button within the region of the attached blocks.
The color of those blocks below the mouse pointer will turn black.
Click the left mouse button to dettach those
black blocks to the spring.
If you click the right mouse button and drag
the force exerted on the spring will not balance the weight of the mass.
It will starts to oscillate in simple harmonic oscillation (SHM)
Press Stop button to reset the spring
back to equilibrium position.
Press Reset button to reset parameters
to default values.
Find out the spring-constant?
Green dot is the equilibrium position. How to determine the smpiltude of
Measure the peroid of the oscillation. What is the relation between mass
and the period?
What else did you find out?
If a spring with a mass attached to it is slightly stretched or compressed
and then let loose,
Many elastic systems (building, flagpoles, airplane wings, etc) behave
in a very similar fashion.
Your suggestions are highly appreciated! Please click firstname.lastname@example.org
Author¡GFu-Kwun Hwang, (Click for more than 40 physics related java applets)
Dept. of physics, National Taiwan Normal University
Last modified :