Urgent Maths Help Needed!!!!!!!! Paper after 5 days

[Ahsen420]

Can Somebody Help with this paper (Maths P21, ON 2010)
http://www.xtremepapers.me/CIE/Cambridg ... _qp_21.pdf
Q5(a)
Q18
Q21(b)

 

[CaptainDanger]

ALREADY ANSWERED IN THE TOPIC YOU POSTED


Q5(a)
The answer is 5... Don't take the plane on which its laying....

Q18
(a) i- Don't you know how to draw tangents?
ii- Take the gradient of the tangent it will give you ACCELERATION... (only in speed time graph)
(b) As you can see from the graph the max speed is 60 m/s, Time given is 13 seconds....

So use the speed distance and time formula...
Distance= 60 into 13 = 780 m/s in the answer..
Q21(b)

You have to use the formula of midpoint here... [(x1 + x2)/2 , (y1 + y2)/2]

[(1 + 7)/2 , (8 + (-4)/2]
[8/2 , (8 -4)/2]
[8/2 , 4/2]
(4,2) is the midpoint...

I hope you get it...

 

[CaptainDanger]

What are you not getting in that part? Its simple... Using the speed formula you have to find the answer....

 

[Ahsen420]

I tried with the accelration formula but its doesn't work
The answer I get is 19/7=2.7
In the Mark Scheme its written 4.4 to 6
I didn't even get it in between

 

[CaptainDanger]

You have to find the gradient of the line you draw? Can you post the line you have drawn here?

 

[Ahsen420]

Here you go man ....
See the question on the paper. I have drawn on the same paper.......

 

[CaptainDanger]

Good Work! :good: But make that line a bit thinner.... And wait let me check if the gradient is correct or not...

 

[Ahsen420]

Now what 2 do

 

[CaptainDanger]

You have drawn the tangent wrong... Wait...

 

[CaptainDanger]

Taking these two points find the gradient... (10,34) and (5,8).... Answer is 5.2... The tangent needs to be "just touching" t=7 on the curve...

 

[Ahsen420]

Sorry for the inconvenience but my question was:
What is the acceleration at t=7

 

[CaptainDanger]

No need to say sorry... The gradient of the tangent at t=7 gives you acceleration....