Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

secondary 4 | A Maths
One Answer Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
MM
MM

secondary 4 chevron_right A Maths chevron_right Singapore

Help to solve

Date Posted: 4 years ago
Views: 197

See 1 Answer

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
1st
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.
Eric Nicholas K
Eric Nicholas K
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.
MM
MM
4 years ago
Thank you sir
MM
MM
4 years ago
Thank you sir