# The equation of motion is given by s=sin2πt (m) . Find the acceleration after 4.5 sec

by russjai
Tags: algebra, calculus, confusing
 P: 7 1. The equation of motion is given by s=sin2πt (m) . Find the acceleration after 4.5 seconds 3. The attempt at a solution Im getting confused on whether the above equation is for velocity or distance. I know the derivative of distance is velocity and that the derivative of velocity is acceleration. If i take the derivative of the above equation i end up with Sa=cos 2π This eliminates T , So im not sure what im doing wrong. Thanks in advance for help. Cheers
 Sci Advisor HW Helper Thanks P: 25,235 Yes, s is distance. But the derivative d/dt sin(2*pi*t) definitely isn't cos(2*pi). Use the chain rule. What's the derivative of sin(t)? Does the t disappear?
 P: 7 Ok would i be correct in saying the derivative of S=sin2πt is Sv=2π cos 2πt ?
HW Helper
Thanks
P: 25,235
The equation of motion is given by s=sin2πt (m) . Find the acceleration after 4.5 sec

 Quote by russjai Ok would i be correct in saying the derivative of S=sin2πt is Sv=2π cos 2πt ?
Yes, you would.
 P: 7 So to get the derivative of Sv=2π cos 2πt to find acceleration . Would i just use the chain rule again? If so does this look correct ? Sa=2π^2 sin 2πt? thanks