Cool-Light
Badges: 2
Rep:
?
#1
Report Thread starter 6 years ago
#1
A particle is moving with constant acceleration in a straight line. It passes through three points, A, B and C with speeds 20m/s, 30m/s and 45m/s respectively. The time taken to move from A to B is t1 seconds and the time taken to move from B to C is t2 seconds.

a) show that t1/t2 = 2/3 (done)

Given also that the total time taken for the particle to move from A to C is 50 seconds,

b) find the distance between A and B? (need help with this part please)

I need to find the value of t1 and t2? I think t2 = 3/2t1 (not too sure, re-arranged t1/t2 = 2/3 to get t2 = 3/2t1) - what do I do after this, what is the value for T1? Please don't provide the answer, give me hints please
0
reply
tiny hobbit
Badges: 15
Rep:
?
#2
Report 6 years ago
#2
(Original post by Cool-Light)
A particle is moving with constant acceleration in a straight line. It passes through three points, A, B and C with speeds 20m/s, 30m/s and 45m/s respectively. The time taken to move from A to B is t1 seconds and the time taken to move from B to C is t2 seconds.

a) show that t1/t2 = 2/3 (done)

Given also that the total time taken for the particle to move from A to C is 50 seconds,

b) find the distance between A and B? (need help with this part please)

I need to find the value of t1 and t2? I think t2 = 3/2t1 (not too sure, re-arranged t1/t2 = 2/3 to get t2 = 3/2t1) - what do I do after this, what is the value for T1? Please don't provide the answer, give me hints please
...and t1 + t2 = 50
1
reply
Crydamoure
Badges: 11
Rep:
?
#3
Report 6 years ago
#3
Been a while since I've done this, so apologies if I make any mistakes.

a = (v-u)/t
rearrange to give
t = (v-u)/a

(30-20)/a = 10/a
(45-30)/a = 15/a

(10/a)/(15/a) = 2/3

Using equations of motion...

t1+t2= 50
t2 = 3/2t1

t1 + (3/2t1) = 50
5/2t1 = 50, solve for t1
thus t1 = 20 (50 / (5/2) = 20)
thus t2 = 30 (20 + t2 = 50)

s ?
u 20
v 30
a not given
t 20

using s = 1/2(u+v)t
s = 1/2(20+30)x20 = 500m

------------------------------ checking answer...

s = ut + 1/2at^2
s - ut = 1/2at^2
2(s - ut) = at^2
2(s - ut)/t^2 = a
a = 0.5

a = v-u/t
(30-20)/20
a = 0.5

Hopefully this is correct, as both a values match.
0
reply
MathMeister
Badges: 10
Rep:
?
#4
Report 6 years ago
#4
(Original post by Crydamoure)
...
Would you reckon this is an A-grade question?
0
reply
Crydamoure
Badges: 11
Rep:
?
#5
Report 6 years ago
#5
(Original post by MathMeister)
Would you reckon this is an A-grade question?
No. Am I incorrect in my working?
0
reply
MathMeister
Badges: 10
Rep:
?
#6
Report 6 years ago
#6
(Original post by Crydamoure)
No. Am I incorrect in my working?
I wouldn't know if you're wrong. It looks quite hard though. What would an A grade question for M1 look like then?
0
reply
Crydamoure
Badges: 11
Rep:
?
#7
Report 6 years ago
#7
(Original post by MathMeister)
It looks quite hard though. What would an A grade question for M1 look like then?
Welcome to A-level maths...

Try looking towards questions 8/9/10 (last few) in OCR M1 past papers. Unfortunately I can't recall one from the top of my head, but you'll find plenty there. Questions are usually presented in the form of a diagram with large blocks of text within which you have to pick out desired information, and this information is not always quantitative (i.e. instead of saying "A particle at point A is at 0ms^-1", it will say "A particle at point A is at rest", effectively meaning the same thing but without any numbers involved).

The question currently under discussion is probably one which would occur within the first three questions of the paper.
0
reply
MathMeister
Badges: 10
Rep:
?
#8
Report 6 years ago
#8
(Original post by Crydamoure)
...
I think I may have actually of solved this one before... I will check out the OCR Mechanics questions.
They seem harder than edexcel
0
reply
DelenaxxStelena
Badges: 6
Rep:
?
#9
Report 6 years ago
#9
(Original post by MathMeister)
I think I may have actually of solved this one before... I will check out the OCR Mechanics questions.
They seem harder than edexcel
inb4 the edexcel haters say it isn't

cie > ocr MEI > Edexcel . wJEC

But then in Edexcel you get those bull**** papers reguarly i.e. C3 June 2013 so hard to say..
0
reply
MathMeister
Badges: 10
Rep:
?
#10
Report 6 years ago
#10
(Original post by DelenaxxStelena)
inb4 the edexcel haters say it isn't

cie > ocr MEI > Edexcel . wJEC

But then in Edexcel you get those bull**** papers reguarly i.e. C3 June 2013 so hard to say..
What was so bad about the C3 June 2013 paper? I've heard people say it was awful many times .
0
reply
davros
  • Study Helper
Badges: 16
Rep:
?
#11
Report 6 years ago
#11
(Original post by MathMeister)
What was so bad about the C3 June 2013 paper? I've heard people say it was awful many times .
Nothing was technically wrong with it; it just caught out a lot of students who didn't fully understand the material and expected the paper to look like all the past papers they'd done before. In future, there should be more papers like it as the intention is to test students' thinking skills more!
0
reply
MathMeister
Badges: 10
Rep:
?
#12
Report 6 years ago
#12
(Original post by davros)
Nothing was technically wrong with it; it just caught out a lot of students who didn't fully understand the material and expected the paper to look like all the past papers they'd done before. In future, there should be more papers like it as the intention is to test students' thinking skills more!
So if you learnt all the material properly you'd not find an issue with it?
0
reply
davros
  • Study Helper
Badges: 16
Rep:
?
#13
Report 6 years ago
#13
(Original post by MathMeister)
So if you learnt all the material properly you'd not find an issue with it?
The final question was a bit wordy and contained some irrelevant information which needed to be ignored, but everything on the paper was within the A level syllabus
0
reply
DelenaxxStelena
Badges: 6
Rep:
?
#14
Report 6 years ago
#14
(Original post by MathMeister)
What was so bad about the C3 June 2013 paper? I've heard people say it was awful many times .
(Original post by davros)
Nothing was technically wrong with it; it just caught out a lot of students who didn't fully understand the material and expected the paper to look like all the past papers they'd done before. In future, there should be more papers like it as the intention is to test students' thinking skills more!
This I suppose, but anyone who said it was a good paper either got 100ums or didn't sit it.

Check the paper yourself.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (17)
19.32%
I'm not sure (2)
2.27%
No, I'm going to stick it out for now (24)
27.27%
I have already dropped out (3)
3.41%
I'm not a current university student (42)
47.73%

Watched Threads

View All