Eric Nicholas K's answer to MM's Secondary 4 A Maths Singapore question.
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If a particle is going to change direction, it must first slow down, reach a zero velocity and then turn back.
So, if a particle is going to turn around, it must have reached v = 0 at some point.
Since our v is more than 5/2 for all values of t (and in fact, more than 7/2 for all t > 0), there can never exist a time that v = 0.
Hence, the particle moves forward all the time and will never turn back and change direction.
So, if a particle is going to turn around, it must have reached v = 0 at some point.
Since our v is more than 5/2 for all values of t (and in fact, more than 7/2 for all t > 0), there can never exist a time that v = 0.
Hence, the particle moves forward all the time and will never turn back and change direction.
Date Posted:
4 years ago
This is very important as we can then realise that the particle does not move backwards at all. Our calculated distance later will therefore be the same as the displacement of the object (since the particle is not going to return), so that we can calculate the distance travelled easily later on.
Thank you sir
Thank you sir
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