Amount of time for a half period to occur

[Capncanada]

Homework Statement

A mass-spring system has k = 105 N/m and m = 1.75 kg.

If it is undergoing simple harmonic motion, how much time does it take the mass to go from x = A to x = 0?

Homework Equations

T=2pi*sqrt(m/k)

The Attempt at a Solution

Tried plugging in the values for the equation I gave to find T, then cutting it in half to find the amount of time the question asked for, but it's not the correct answer.

 

[vela]

What exactly is one cycle? If you understand that, you'll see why your answer is wrong. It may help to look at a diagram that shows one period in your textbook.

 

[Capncanada]

When the mass goes into the spring and back?

 

[ehild]

Sketch the x(t) function for a full period and see.

ehild

 

[vela]

When the mass goes into the spring and back?

Yes. So in one cycle, if it starts at x(0)=A, it ends at x(T)=A, but more important, what does x(t) do in between? As ehild suggested, plot x(t) for one cycle.

 

[dextercioby]

Who's A and can you link it to T ? EDIT: So A's the amplitude...

 

[Capncanada]

Uhh x goes to A? Which equation can I use to solve for that? x=Acos(ωt)?

Sorry I'm braindead been studying all morning I just want this homework done.

 

[ehild]

Which equation can I use to solve for that? x=Acos(ωt)?

Yes. x = A cos (2pi* t/T). How does it look like? What is x at t=0, t=T/8, T/4, ...

ehild

 

[Capncanada]

So I can plug in x as A so that A cancels out here and then solve for t where T = 1/2?

 

[ehild]

So I can plug in x as A so that A cancels out here and then solve for t where T = 1/2?

Is T=1/2??


Would you please show me a cosine function? Please!

ehild