heyy
so i keep trying this question but i keep getting it wrong so i decided to try macinsiders..since there are such smart ppl on here lol

A spring is suspended from a ceiling and has a block attached to its lower end. The block is held a distance y1 from the ceiling (at this point the spring is at its rest length) and released. The block oscillates up and down with its lowest point being 0.118 m below y1. Calculate the speed of the block when it is 0.077 m below the release point at y1.




Any help would be much appreciated
Sandra

hi,

From the top of my head, I think you could use
Ek=Wsp
=-kx delta d
Then solve backwards for the speed.

However, you need more information, were there parts to this question? You could use those values to solve for it.

I am 100% sure but I would've tried that...Hope that helps

we werent given anything except the distances shown in the questions...the question previous to this we had to calculate frequency :S but im still lost :(

oh okay... forget what I said before.
Isolate for a variable in the equation you used for frequency and then sub it into the equation below.

Use the equation:
E=K+U
1/2kA^2= 1/2m(v2-v1)^2 + 1/2k(y2-y1)^2

for 'A', it is 0.118- y1. some of your variables should cancel out in the end.

Play around with the equation once you've subbed the frequency equation into it, and you should get the answer.

Hopefully that works for you

I think you're doing a simple harmonic motion question and so you're going to need the SHM functions. Namely the second order differential equation you probably saw in class and was solved for you.

You found the frequency which we will need.

We are going to make use of two equations (w is omega):

x(t ) = A cos (wt)
v(t ) = -A*w*sin (wt)

We know A = 0.118m because the question gives that to us. w = 2pi/T, so you know the value of that too. Remember T=1/f. x(t ) = 0.077m because that is the point of interest. Solve for t (time).

Then use the v(t ) equation to solve for v(t )by subbing in t which in found from the previous equation, which will give you the velocity when the block is at 0.077m

I'm pretty sure this is right. I didn't solve the equations so I don't have any numbers.