acc/velocity rate of change (2 Viewers)

[Tryingtodowell]

Idk if im missing a bit of theory here but why is b incorrect?

 

[wollongong warrior]

Unless they mean O as in literally some position O instead of the origin then b is correct? The only option wrong is c

 

[Tryingtodowell]

Unless they mean O as in literally some position O instead of the origin then b is correct? The only option wrong is c

idk it says in the answers that b is incorrect as well as c

 

[Tryingtodowell]

btw dont u integrate for part a (Idk what im on about and I havent learnt integration yet)

 

[wollongong warrior]

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btw dont u integrate for part a (Idk what im on about and I havent learnt integration yet)

Yes

 

[liamkk112]

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btw dont u integrate for part a (Idk what im on about and I havent learnt integration yet)

i feel like u should learn integration first lol

 

[Tryingtodowell]

i feel like u should learn integration first lol

isnt integration yr 12?? its not like I skipped topics
this is in year 11
(learning it this term anyways)

 

[liamkk112]

isnt integration yr 12?? its not like I skipped topics
this is in year 11
(learning it this term anyways)

integration is year 12 but like idk how u would do these questions without it

 

[Average Boreduser]

View attachment 43593
Idk if im missing a bit of theory here but why is b incorrect?

You have to integrate. It literally has C in the solution for x lmao

 

[Tryingtodowell]

integration is year 12 but like idk how u would do these questions without it

idk it was just a subpart and there was no more questions like that

 

[Average Boreduser]

idk it was just a subpart and there was no more questions like that

Then this must be an old syllabus paper? Only other way i'd approach this question is differentiating the subpart (a) and showing it's equal to x(dot)? But surely that could have been worded better lmao

 

[Tryingtodowell]

Then this must be an old syllabus paper? Only other way i'd approach this question is differentiating the subpart (a) and showing it's equal to x(dot)? But surely that could have been worded better lmao

its not a past paper
its textbook work

 

[Average Boreduser]

its not a past paper
its textbook work

regardless, the method you took (I'm assuming you differentiated x to see if it satisfied x(dot). the reason why b is wrong is because you didn't take into consideration about constants that may actually be present in the displacement function. it doesn't ask for 'possible graphs', rather its directly asking if said statement was correct. whilst 3t^2-4 wtv is a possible solution of x, it doesn't provide the general case which considers all functions with the same gradient function which may or may not include constants . all in all-> wait till you learn integration and everything should sink into place.