- #1
Terp
- 41
- 0
Hi everybody, this problem is giving me trouble and I was wondering if you could give me any advice.
The velocity of an object in simple harmonic motion is given by vx(t)= - (0.35 m/s)sin(20t + pi), where t is in s.
What is the first time after t=0s at which the velocity is - 0.25 m/s?
See the equation above.
I simply plugged -.25 m/s in for vx(t) above and solved for t, so I got:
-0.25 = -0.35sin(20t + pi)
.714 = sin(20t + pi)
When I solve for t I get t = -.397e-1 = -.0397s, but mastering physics (the program I use to do homework online) say it's wrong. I entered the answer as positive. Anybody have any idea? Thanks a lot!
edit: I just went to see my professor and he helped me set it up, when finished we had sin(20t) = -5/7, but master physics says it's wrong.
Homework Statement
The velocity of an object in simple harmonic motion is given by vx(t)= - (0.35 m/s)sin(20t + pi), where t is in s.
What is the first time after t=0s at which the velocity is - 0.25 m/s?
Homework Equations
See the equation above.
The Attempt at a Solution
I simply plugged -.25 m/s in for vx(t) above and solved for t, so I got:
-0.25 = -0.35sin(20t + pi)
.714 = sin(20t + pi)
When I solve for t I get t = -.397e-1 = -.0397s, but mastering physics (the program I use to do homework online) say it's wrong. I entered the answer as positive. Anybody have any idea? Thanks a lot!
edit: I just went to see my professor and he helped me set it up, when finished we had sin(20t) = -5/7, but master physics says it's wrong.
Last edited: