Amount of time for a half period to occur

Capncanada

1. The problem statement, all variables and given/known data

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?

2. Relevant equations

T=2pi*sqrt(m/k)

3. 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

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

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

Is T=1/2???????


Would you please show me a cosine function? Please!!!!

ehild