OCR Maths (MEI) M1 2014

Well for the first ones:

1. Area of triangle = 20m
Area of trapezium = 150m
ii) Diagram shows distance up to the 20m then to 140m (after 16s) and then to 150m (after 18s)

2. i) Show that p + q was parallel: should be 3.5(8i - j) or something like that
ii) show that k = -4 and then calculate the mass of the object: so the weight = 24.5 and mass = 2.5kg
iii)3p + 10q = 196i and no vertical component

3.i) Show vector triangle
ii) Rearrange into equations
iii) Draw diagram showing sine and cosine curve and 45<alpha<=90

4i)v=0 find the roots of quadratic t=4 and -3 discard -ve answer
ii)integrate v to get s. I got 400 000km
iii)differentiate to get a, require a=0 so t=2. max speed is 150 000km/h

And for the rest I remember bits and pieces...

(edited 9 years ago)

Reply 83

Dan205

8

What kind of grade boundaries d'you guys reckon? I'm thinking medium ish?

Reply 84

Original post by Dan205

What kind of grade boundaries d'you guys reckon? I'm thinking medium ish?

I personally found the paper easy, and expect around 95% - but then I'm an A2 student...... It wasn't as hard as the June 13 one...
I think that the sine, cosine thing and that whole vector thing would have thrown people. But the last 2 questions were straight-forward compared to 2013, no? And they gave you the answers for the projectile - you just had to show working....

So maybe an A would be 58/59?

Reply 85

2iii) 3p+10q=196i
no j component so horizontal

3iii) and 45<alpha<=90
4i)v=0 find the roots of quadratic t=4 and -3 discard -ve answer
ii)integrate v to get s. I got 400 000km
iii)differentiate to get a, require a=0 so t=2. max speed is 150 000km/h

Reply 86

Original post by AndyChow

2iii) 3p+10q=196i
no j component so horizontal

3iii) and 45<alpha<=90
4i)v=0 find the roots of quadratic t=4 and -3 discard -ve answer
ii)integrate v to get s. I got 400 000km
iii)differentiate to get a, require a=0 so t=2. max speed is 150 000km/h

Yeah - I got all of these.

Reply 87

Dan205

8

Original post by Surf

I personally found the paper easy, and expect around 95% - but then I'm an A2 student...... It wasn't as hard as the June 13 one...
I think that the sine, cosine thing and that whole vector thing would have thrown people. But the last 2 questions were straight-forward compared to 2013, no? And they gave you the answers for the projectile - you just had to show working....

So maybe an A would be 58/59?

Yeahh that's about the kind of boundaries i'm hoping for. In my opinion the toughest thing about this year's paper was getting it all done in the time limit :/

Reply 88

Original post by Dan205

Yeahh that's about the kind of boundaries i'm hoping for. In my opinion the toughest thing about this year's paper was getting it all done in the time limit :/

I think that's the same for most A level exams!!! I always have problems with that.... but today was surprisingly okay - I finished with 15mins to spare....

You got through it all though right?
How do you think you've done?

This exam was a joke

Q4 is the cannon one
i)use s=ut+0.5at^2
-75=20sin30t-5t^2
you get t=5

horizontal range:
x=20cos30 x 5
so x=86.6m
90-86.6=3.4m <5m so hit water less than 5 m from boat

ii)longer since flight time is longer and horizontal velocity remain constant

Q7
i)N2L on whole train
120000-2000-500-500=(90000+2x30000)a
a=0.06ms^-2

ii)N2L on truck B
T-500=30000x0.06
T=2300N

iii)N2L on whole train
-2000-5000-500=150000a
a=-0.05ms^-2

SUVAT s=u^2-v^2/2s you get 1000m

N2L on truck B
-500+T=30000x-0.05
T=-1000N so thrust

iv)horizontal equilibrium on whole system
120000-2000-500-500-150000gsin(alpha)=0
alpha=0.351deg (3sf)

v)equilibrium on truck B
T-30000gsin0.351-500=0
T=2300N as before

Anyone want to start a mark scheme?

(edited 9 years ago)

Reply 91

1. Area of triangle = 20m
Area of trapezium = 150m
ii) Diagram shows distance up to the 20m then to 140m (after 16s) and then to 150m (after 18s)

2. i) Show that p + q was parallel: should be 3.5(8i - j) or something like that
ii) show that k = -4 and then calculate the mass of the object: so the weight = 24.5 and mass = 2.5kg
iii)3p + 10q = 196i and no vertical component

3.i) Show vector triangle
ii) Rearrange into equations
iii) Draw diagram showing sine and cosine curve and 45<alpha<=90

Q4 is the cannon one
i)use s=ut+0.5at^2
-75=20sin30t-5t^2
you get t=5

horizontal range:
x=20cos30 x 5
so x=86.6m
90-86.6=3.4m <5m so hit water less than 5 m from boat

ii)longer since flight time is longer and horizontal velocity remain constant

5i)v=0 find the roots of quadratic t=4 and -3 discard -ve answer
ii)integrate v to get s. I got 400 000km
iii)differentiate to get a, require a=0 so t=2. max speed is 150 000km/h

Q7
i)N2L on whole train
120000-2000-500-500=(90000+2x30000)a
a=0.06ms^-2

ii)N2L on truck B
T-500=30000x0.06
T=2300N

iii)N2L on whole train
-2000-5000-500=150000a
a=-0.05ms^-2

SUVAT s=u^2-v^2/2s you get 1000m

N2L on truck B
-500+T=30000x-0.05
T=-1000N so thrust

iv)horizontal equilibrium on whole system
120000-2000-500-500-150000gsin(alpha)=0
alpha=0.351deg (3sf)

v)equilibrium on truck B
T-30000gsin0.351-500
T=2300N as before

Reply 92

Moon1ight

54 for an A.that exam was hard but regardless of the grade boundary I've failed.

Reply 93

Q6)
i)speed=root(5squared+10squared)
=11.2ms-1)
angle=arctan0.5=25.6deg
ii)due to weight , air resistance, power unit respectively
iii)put vectors in the equation v=u+at and s=s0+ut+1/2at^2 it even tells you a, u and s0 so just put in the vectors. simplify and substitute t=30 s should be (0,0,0) then you get it correct. No need to integrate
iv)substitute t=30 find v. v is too fast (-40ms-1 vertically) so unrealistic.

(edited 9 years ago)

Reply 94

Original post by krishkmistry

54 for an A.that exam was hard but regardless of the grade boundary I've failed.

Yeah, I'm sorry you didn't do great. But I don't think that it was harder than June 13; and grade boundaries for that were 58 or something like that - so I think 59 or around that is realistic.

Original post by AndyChow

Q6)
i)speed=root(5squared+10squared)
=11.2ms-1)
angle=arctan0.5=25.6deg
ii)due to weight , air resistance, power unit respectively
iii)put vectors in the equation v=u+at and s=s0+ut+1/2at^2 it even tells you a, u and s0 so just put in the vectors. simplify and substitute t=30 s should be (0,0,0) then you get it correct. No need to integrate
iv)substitute t=30 find v. v is too fast (-40ms-1 vertically) so unrealistic.

And again, I got the same.

Reply 95

Original post by Surf

Yeah, I'm sorry you didn't do great. But I don't think that it was harder than June 13; and grade boundaries for that were 58 or something like that - so I think 59 or around that is realistic.

And again, I got the same.

Nice

I thought s1 is easy so M1 has to be hard. But that wasn't the case. There isn't many tricky questions in this paper. Section B questions was a joke compared to past ones. Then only ones worth mentioning is triangle of forces. Many people didn't get R=Wcos(alpha) and S=Wsin(alpha)

Reply 96

Original post by AndyChow

Nice

I thought s1 is easy so M1 has to be hard. But that wasn't the case. There isn't many tricky questions in this paper. Section B questions was a joke compared to past ones. Then only ones worth mentioning is triangle of forces. Many people didn't get R=Wcos(alpha) and S=Wsin(alpha)

Yeah the train one a couple of years ago was much harder than the one today. And yeah, while I was doing it I thought that the triangle of forces would throw a few people....

The sky-diving one they gave you most of the answers - or you could check them with questions later on (like prove that she is at the origin) and the same thing with the last question (use the angle to show that the force in the rod is the same as part blah blah).... so yeah - it wasn't a tricky paper.

Guessing you are thinking 95-100% then!

Reply 97

actually Q6iii) you add the forces and use N2L
a=(0.5, -0.2, -1)

Reply 98

a96clark

12

Q7)iii) anyone? The one about the carriage B having the new resistance and finding the thrust or tension in the coupling?

Reply 99

Moon1ight