# SMH-Block Attached to a spring

1. May 20, 2017

### Physicist1234

1. The problem statement, all variables and given/known data
A block with mass m = 1.7 kg attached to the end of a spring undergoes simple harmonic motion on a horizontal frictionless surface. The oscillation period is T = 4.3 s and the oscillation amplitude is A = 29.6 cm. When the spring is unstretched the block sits at a distance L = 1.7 m from a wall. Suppose we snap the spring at the very moment the block passes through the equilibrium point towards the wall. Calculate the time it takes for the block to hit the wall.

2. Relevant equations
w=2*Pi*f=2*Pi/T=sqrt(k/m)
x=Acos(wt)

3. The attempt at a solution
w=2*Pi/4.3=1.46. I'm not sure how to go about using the above formulas

2. May 21, 2017

### AlphaLearner

Please use proper signs and symbols. By hitting the 'Σ' button, you see vast signs and symbols. Use subscript and superscript. Use 'x' for into instead of *.

3. May 21, 2017

### ehild

Calculate the velocity when the block is at the point when the spring is just relaxed. You cut the spring, so the block moves with that velocity towards the wall, 1.7 m away. How long does it take to reach the wall?

4. May 21, 2017

### AlphaLearner

Last edited: May 21, 2017
5. May 21, 2017

### AlphaLearner

Else, since spring was snapped, there wont be any acceleration by any source. Means block moves with constant velocity, taking velocity at mean position as initial and final as 0 (since block crashes the wall) Apply s = ut (s=1.7m, u=Aω2), you get required value 't'.

Last edited: May 21, 2017
6. May 21, 2017

### ehild

The speed at the equilibrium position is Aω, and constant after the spring is cut.

7. May 21, 2017

### AlphaLearner

True, it is Aω
V = ω√A2-x2
At mean position 'x' is 0. By solving, we get Aω.
Sorry for wrong information.