Simple Harmonic Motion Question

[FsLiu]

Homework Statement

Homework Equations

x = A cos(wt-phi)

The Attempt at a Solution

Using the above equation for t, calculating values for t₁ at -0.05 and t₂ at 0.05, as well as assuming phase angle phi is zero, I get an answer of over 40 seconds.

I think I may be using the wrong equation or perhaps assuming the value of phi incorrectly. Help is appreciated.

 

[zhermes]

What values are you using for that equation (i.e. what A and omega ['w']) ?

 

[FsLiu]

What values are you using for that equation (i.e. what A and omega ['w']) ?

Those are both given in the original question, A=0.100m and w=2pi(period inverse) which turns out to be 1.48 Hz

 

[zhermes]

I don't see how you could be getting > 40s; can you show us how you solved for t?

 

[FsLiu]

I don't see how you could be getting > 40s; can you show us how you solved for t?

Yeah that's the problem, doesn't make sense logically/physically.

I used the equation x = A cos(wt-phi), assumed phi was zero and rearranged for time, t.

Then I did t1 at -0.05m and t2 at +0.05m and then took the difference as the time taken to go from point one to point 2.

 

[zhermes]

There must be something wrong with your algebra, could you show your expressions for t