# General Thoughts. (1 Viewer)

#### Grenot

##### New Member
Give me the question and I can probably work it out for you.
I can't remember the exact question, but it was along the lines of
5mm of rain fell onto a 216m^2 roof. The water was then funnelled into a cylindrical tank that had a diameter of 3.6m.
What was the increase in height of the cylindrical tank.

#### BLIT2014

##### The pessimistic optimist.
Moderator
I can't remember the exact question, but it was along the lines of
5mm of rain fell onto a 216m^2 roof. The water was then funnelled into a cylindrical tank that had a diameter of 3.6m.
What was the increase in height of the cylindrical tank.
I'm slightly sleep deprived but you do something like this

Area of Base of Roof=216m
Volume of water on roof =H1*A2
= 216* .005
=0.08m3

Area of Base of Tank = πr2 = π*1.8

V=πr 2h
0.08m3= π*3.6 * h
0.08m3/( π*3.6)=h
0.00707355302m^2=height

Therefore the increase in the height of the cylindrical trunk was 7.07mm

#### BLIT2014

##### The pessimistic optimist.
Moderator
I can't remember the exact question, but it was along the lines of
5mm of rain fell onto a 216m^2 roof. The water was then funnelled into a cylindrical tank that had a diameter of 3.6m.
What was the increase in height of the cylindrical tank.
Firstly we need to work out the volume of water on the roof

Volume of a cylinder is
V=πr2h

Then we sub the v=volume of water on roof, h is unknown and what we are finding, and r=1.8

#### BLIT2014

##### The pessimistic optimist.
Moderator
Anyone have a copy of the paper?

#### Loudvicuna

##### Active Member
I'm slightly sleep deprived but you do something like this

Area of Base of Roof=216m
Volume of water on roof =H1*A2
= 216* .005
=0.08m3

Area of Base of Tank = πr2 = π*1.8

V=πr 2h
0.08m3= π*3.6 * h
0.08m3/( π*3.6)=h
0.00707355302m^2=height

Therefore the increase in the height of the cylindrical trunk was 7.07mm
You fucked up your V value, 1.08/1000 = 0.00108m^3

The correct working is
A=n*1.8^2
=10.179

Volume of water = 216*0.005
=1.08m^3

1.08=10.179h
h = 10.6cm increase

I got 10.6cm as my answer but made 2 errors in my working for my exam where I mixed capacity and volume so I'll only get a mark

Last edited:
• BLIT2014

#### BLIT2014

##### The pessimistic optimist.
Moderator
You fucked up your V value, 1.08/1000 = 0.00108m^3

The correct working is
A=n*1.8^2
=10.179

Volume of water = 216*0.005
=1.08m^3

1.08=10.179h
h = 10.6cm increase

I got 10.6cm as my answer but made 2 errors in my working for my exam where I mixed capacity and volume so I'll only get a mark
In putting the diameter instead was especially stupid for me given the fact I wrote Area of Base of Tank = πr2 = π*1.8

#### swagmeister

##### Active Member
You fucked up your V value, 1.08/1000 = 0.00108m^3

The correct working is
A=n*1.8^2
=10.179

Volume of water = 216*0.005
=1.08m^3

1.08=10.179h
h = 10.6cm increase

I got 10.6cm as my answer but made 2 errors in my working for my exam where I mixed capacity and volume so I'll only get a mark
see I found it was easier to convert this question to cm cubed, then go from there...

but yeah I got 10.6cm increase as well

if you got errors how did you reach that as your answer?

#### Loudvicuna

##### Active Member
see I found it was easier to convert this question to cm cubed, then go from there...

but yeah I got 10.6cm increase as well

if you got errors how did you reach that as your answer?
I made 2 errors which gave me the correct answer lol. When finding volume of water on roof I got 1.08L instead of m3
Then when finding height I subbed in 1.08L as V instead of 1.08m3

#### swagmeister

##### Active Member
I made 2 errors which gave me the correct answer lol. When finding volume of water on roof I got 1.08L instead of m3
Then when finding height I subbed in 1.08L as V instead of 1.08m3
Evidently luck was on your side...
May loose a mark for incorrect working though?

#### swagmeister

##### Active Member
Hey guys

Jus wanted to ask for mc, the question asking you to find the side of something and gave you the area as 250cm squared or smthing, was the angle (sin44) included???
sorry for the late reply, wasn't sure about the question till I got a copy of the paper (didn't fully remember it)

but yeah, it was - so I just used the area sine rule and the worked out x from there

#### diggler

##### New Member
Not sure what they wanted in 29 c with the diver. Don't you just read the height off the graph? 2 marks?

26g mobile phone question, were you supposed to use the formula sheet to convert 1.7 GB into MB? I got \$96.36 for that.

Similarly for 27e. I got 11 min 28 secs for that.

#### diggler

##### New Member
If anybody wants to compare answers, this is what I got.

1d 2a 3b 4a 5b 6c 7b 8c 9b 10a 11d 12c 13a 14c 15b 16d 17c 18a 19d 20a 21c 22d 23d 24b 25c

26a 117

26b 3

26c 4468km

26d \$369.17

26e(i) 0.17 (ii) 0.86

26f 365450163.7km sq

26g \$96.36

27a 58.18m

27b 50

27c (i) \$250 (ii) 65

27d (i) outlier (ii) none

27e 11min 28 sec

28a 50.27cm sq

28b better in English

28c 4000 cm sq

28d 37.4 deg f

28e (ii) 10cm (iii) Dots not on line.

28f (i) C = 2100 + 0.5N (ii) 700

29a \$427.57

29b \$100480

29c (i) 12m x 18m (ii) 0.106m

29d (i) \$392,000 (ii) \$385,250

29e Highest point of graph

30a \$240.61

30b 48/95

30c (i) \$11136.89 (ii) \$407.03

30d 120.31m

30e 1.37m

#### Em7

##### New Member
I'm pretty sure it did from memory

#### Em7

##### New Member
It was overall pretty good. Not sure if that's because I didn't know what I was doing hehe
It seemed like a good combination of being difficult but not too much.
Hopefully it wasn't easy for a bad reason.

#### Em7

##### New Member
It was declining because it had a percentage.
Straight-line method takes off a fixed amount which we weren't given to take away

#### DLMisme

##### Active Member
I actually didn't find the exam as bad as I expected. Maths isn't my strong point, but I feel reasonably confident. My only issue was time management, I was a little bit slow and had to rush toward the end to finish.