00:01
So here we have simple harmonic motion and this would be modeled by x position as a function of time equaling the amplitude times cosine of the angular frequency multiplied by time plus the phase constant.
00:15
The velocity in the x -direction as a function of time would be equaling to the negative amplitude multiplied by the angular frequency multiplied by sine of the angular frequency multiplied by time plus again the phase constant.
00:29
So we need to then determine the angular frequency, the phase constant, and the amplitude.
00:37
So we can first start off by saying the period equaling 2 pi multiplied by the mass over the spring constant k.
00:46
This would be equaling to 2 pi multiplied by 1 .0 kilograms.
00:52
This would be divided by 20 neutins per meter.
00:56
And this is giving us 1 .405 seconds.
01:00
So the angular frequency would then be equaling to 2 pi divided by t, the time period, 2 pi divided by 1 .405 seconds.
01:12
And this is giving us then 4 .472 radians per second.
01:20
We know that initially we can say at t equaling 0 seconds, the initial position equals the amplitude multiplied by cosine of phi not and we know that the initial velocity in the x direction would be equaling to negative a omega sine of phi not dividing these two equations we can say that then tangent of phi not would be equaling the negative initial velocity in the x direction divided by the angular frequency multiplied by the initial exposition this is equaling to then negative negative 1 .0 meters per second, this would be divided by 4 .472 radians per second, multiplied by 0 .20 meters.
02:19
And we find that then this is equaling 1 .1181...