Time an object takes to oscillate

[Liketothink]

Homework Statement

An object in SHM oscillates with a period of 5.73 s and an amplitude of 10.47 cm. How long does the object take to move from x=0 cm to x=5.78 cm?

Homework Equations

x=Acos(wt+ro)

The Attempt at a Solution

I solved for ro which was pi/2 when x=o and t=o. Then I solved for angular speed which was 2pi*frequency. Then I did cos^-1(5.78/10.47)=wt+pi/2 and I solved for t but that did not work. Could you please help me? Thank you.

 

[Redbelly98]

Your equation looks correct.

What did you get for w and t?