Understanding spring mass system

[chandran]

I am just learining basic dynamics from spring mass system.
there is a horizontal spring fixed to the wall and a mass is at the end.
When the mass is displaced by a force F to the right the spring stretches to a distance X. Now i draw the STATIC FBD. The
eqn is f-kx=net force on the mass. Now i draw the kinetic diagram and the equation i derive is

f-kx=ma where a is the acceleration of the mass m. So for this spring mass system the dynamic equation is
f-kx-ma=0.

Is what i have done is true and correct?

 

[dextercioby]

Is the force acting continuously on the object...?Or it just stretches the string & let's it go to oscillate...?

That equation,vector or scalar,f-kx-ma=0 makes no sense...

Daniel.

Daniel.

 

[ramollari]

I am just learining basic dynamics from spring mass system.
there is a horizontal spring fixed to the wall and a mass is at the end.
When the mass is displaced by a force F to the right the spring stretches to a distance X. Now i draw the STATIC FBD. The
eqn is f-kx=net force on the mass. Now i draw the kinetic diagram and the equation i derive is

f-kx=ma where a is the acceleration of the mass m. So for this spring mass system the dynamic equation is
f-kx-ma=0.

Is what i have done is true and correct?

Yes, it is correct as long the hand pulling the mass is not releasing it.

$$F - kx = 0$$

 

[Doc Al]

I am just learining basic dynamics from spring mass system.
there is a horizontal spring fixed to the wall and a mass is at the end.
When the mass is displaced by a force F to the right the spring stretches to a distance X. Now i draw the STATIC FBD. The
eqn is f-kx=net force on the mass.

This is just a statement that the net force on the mass equals f - kx.

Now i draw the kinetic diagram and the equation i derive is

f-kx=ma where a is the acceleration of the mass m. So for this spring mass system the dynamic equation is
f-kx-ma=0.

Now you've applied Newton's 2nd law: Net Force = ma. Note that rewriting it as "Net Force - ma = 0" adds nothing.

If the mass is in equilibrium, then f - kx = 0; if not, then it will accelerate.

 

[marlon]

I am just learining basic dynamics from spring mass system.
there is a horizontal spring fixed to the wall and a mass is at the end.
When the mass is displaced by a force F to the right the spring stretches to a distance X. Now i draw the STATIC FBD. The
eqn is f-kx=net force on the mass. Now i draw the kinetic diagram and the equation i derive is

f-kx=ma where a is the acceleration of the mass m. So for this spring mass system the dynamic equation is
f-kx-ma=0.

Is what i have done is true and correct?

Here, you can learn more on basic dynamics. make sure that you are able to solve the given exercises...

https://www.physicsforums.com/showthread.php?t=72040


marlon