Velocity and Acceleration in terms of x (1 Viewer)

[mac1996]

Hey guys
How would you do these questions attached?

thank you

 

[omgiloverice]

I just found the equation for t so the rest should be obvious

As for part b) I'll give you a clue the value of t must always be positive

Question 11 will have the same kind of manipulation



For the rocket question 11 same manipulation but watch out for the wording at v = 5km/s the value of x will be 6400 km.
For part b) sub v=0 and try to solve for x

 

[mac1996]

I just found the equation for t so the rest should be obvious
View attachment 27995
As for part b) I'll give you a clue the value of t must always be positive

Question 11 will have the same kind of manipulation

Ill post up the solutions for the rest later

For part b would the answer be:
as t>0
so cos2x<0
therefore must be pi/4 ≤ 3pi/4
therefore it is never in between 0 and pi/4

 

[omgiloverice]

therefore must be pi/4 ≤ 3pi/4
therefore it is never in between 0 and pi/4

I don't understand how you managed to get from pi/4< x< 3pi/4 to 0 < x < pi/4

For these kind of questions they already gave you the answer, so just use it and manipulate your way through.

Edit: No not integers values
Edit: You're

 

[mac1996]

my answer is just a vague version of urs
however u made things more clearer thanks man
btw are u able to upload the solutions to the other questions?

 

[omgiloverice]

eh depends I accidentally deleted my entire 5% done chemistry assignment, and I have a mild cold hence the silly mistakes so I'm kinda annoyed.
I'll make the solutions that will direct you to the right path but not the entire thing. Ill upload the solution to question 12 in a moment

 

[HeroicPandas]

eh depends I accidentally deleted my entire 5% done chemistry assignment, and I have a mild cold hence the silly mistakes so I'm kinda annoyed.
I'll make the solutions that will direct you to the right path but not the entire thing. Ill upload the solution to question 12 in a moment

i'll give him a short guide on how to do it:

"if the rocket starts from rest at the SURFACE of the Earth (radius 6400km)"
"where x is the distance from the centre of the earth"

these 2 quotes from the question reveals a special condition that u must use to complete this question (if u cannot see it straight away, draw out a diagram)

CONDITION: v = 0, x = 6400, t=0 <---- Information given(eg. v = blah, x = blah, t = blah

You are given an acceleration equation and they tell u to find a velocity equation in terms of x

So u just simply use one of these formulas:

After integrating use the condition to find C

 

[Currybear]

maths in focus?..... use cambridge