VCE Methods Question Thread!

[Snorlax]

Thought this was a 3/4 thread.

[vcestudent94]

Thought this was a 3/4 thread.

You don't solve linear equations in 3/4?

[Only Cheating Yourself]

Help please units 1 and 2

For safety considerations, wheelchair ramps are constructed under regulated specifications.  One regulation requires that the maximum gradient of a ramp exceeding 1200mm in length 1/14

question.  a 16cm high ramp needs to be built.  Find the horizontal length of the ramp required to meet the specifications.

[Apink]

Help please units 1 and 2

For safety considerations, wheelchair ramps are constructed under regulated specifications.  One regulation requires that the maximum gradient of a ramp exceeding 1200mm in length 1/14

question.  a 16cm high ramp needs to be built.  Find the horizontal length of the ramp required to meet the specifications.

If that's all the information given, then we have to assume the length of the ramp is more than 1200mm (120cm) and therefore the gradient is . The gradient of a linear line is: and in this case, the gradient can be represented as .
The question gives us the vertical length as and the maximum gradient as to find the horizontal length. Let be the horizontal length to make it more simple. So:



The RHS (right hand side) must not be higher than as that is the highest gradient. So it's really:


Sub in the values:


Multiply both sides by :


Multiply both sides by :




horizontal length is at least

Now just to be sure, let's check if the length of the ramp is longer than 120cm using Pythagoras' theorem.











If the horizontal length gets longer, the ramp gets longer too. So the ramp will always be longer than 120cm with this answer.
So it works out.

[Apink]

exactly what i was after but i don't understand why we flip them?  Does the subject have to be on the top?  When its m/ can't you just multiply m when its the numerator?

It's just a short cut. You don't have to flip the fractions. You can flip it like clueless123 and then solve for

or you can do it this way which should be more familiar:



Multiply both sides by




Divide both sides by



You can only flip the fractions on each side ONLY if there's one fraction on each side and nothing else.
Eg.

     can be flipped   

     can be flipped   

     cannot be flipped       NO
You must group the RHS (right hand side) into one fraction so it can be flipped.


   now it can be flipped   

  cannot be flipped       NO
Group the right hand side:


now it can be flipped.   

It is a common mistake not grouping each side before flipping so be careful. I'll admit this isn't a very good explanation but I tried. 

[Only Cheating Yourself]

It's just a short cut. You don't have to flip the fractions. You can flip it like clueless123 and then solve for

or you can do it this way which should be more familiar:



Multiply both sides by




Divide both sides by



You can only flip the fractions on each side ONLY if there's one fraction on each side and nothing else.
Eg.

     can be flipped   

     can be flipped   

     cannot be flipped       NO
You must group the RHS (right hand side) into one fraction so it can be flipped.


   now it can be flipped   

  cannot be flipped       NO
Group the right hand side:


now it can be flipped.   

It is a common mistake not grouping each side before flipping so be careful. I'll admit this isn't a very good explanation but I tried. 

nah its great thanks!

[Only Cheating Yourself]

If that's all the information given, then we have to assume the length of the ramp is more than 1200mm (120cm) and therefore the gradient is . The gradient of a linear line is: and in this case, the gradient can be represented as .
The question gives us the vertical length as and the maximum gradient as to find the horizontal length. Let be the horizontal length to make it more simple. So:



The RHS (right hand side) must not be higher than as that is the highest gradient. So it's really:


Sub in the values:


Multiply both sides by :


Multiply both sides by :




horizontal length is at least

Now just to be sure, let's check if the length of the ramp is longer than 120cm using Pythagoras' theorem.











If the horizontal length gets longer, the ramp gets longer too. So the ramp will always be longer than 120cm with this answer.
So it works out.

i sort of get it…  And yes the answer is correct.  It asks the maximum length of a ramp is 1/14 which is very small so then how can the the horizontal length be 224cm?  Rise over/Run is used to find an equation from a graph isn't it?

[Apink]

i sort of get it…  And yes the answer is correct.  It asks the maximum length of a ramp is 1/14 which is very small so then how can the the horizontal length be 224cm?  Rise over/Run is used to find an equation from a graph isn't it?

The length of the ramp is at least 120cm and the gradient of that ramp is . If the horizontal length of the ramp is 224cm, then the length of the ramp is  225cm.

The isn't just limited to graphs, it can applied to any question where there's an angle. The ramp is on an angle and so it has a gradient. However, we can represent the ramp as a graph. (Check the attachment) 

The equation for that graph would be:
If   

Multiply both sides by 14

[alchemy]

Help please units 1 and 2

I think that it's best you create a Units 1 & 2 Methods thread, or use mine
Year 12's will probably appreciate this thread to be related to Methods 3/4 content only.

[Only Cheating Yourself]

The length of the ramp is at least 120cm and the gradient of that ramp is . If the horizontal length of the ramp is 224cm, then the length of the ramp is  225cm.

The isn't just limited to graphs, it can applied to any question where there's an angle. The ramp is on an angle and so it has a gradient. However, we can represent the ramp as a graph. (Check the attachment) 

The equation for that graph would be:
If   

Multiply both sides by 14

ok thanks heaps!

[Only Cheating Yourself]

Thought i'd make a thread as i was asking too many on the 3-4 one.

[Only Cheating Yourself]

Is anyone doing 1-2 methods and their using the 'quest book' also are you guys doing anything over the holidays for methods?

[alchemy]

I did the content during orientation week before holidays, so I'm mainly working through Checkpoints, past exams and interesting questions that other people post up, when I have time.
If I attempted any more of the textbook now it'll probably end up in "burn out" and forgetting all the content.

[Only Cheating Yourself]

I did the content during orientation week before holidays, so I'm mainly working through Checkpoints, past exams and interesting questions that other people post up, when I have time.
If I attempted any more of the textbook now it'll probably end up in "burn out" and forgetting all the content.

so your doing 1 and 2?  What do you mean you did the content and you bought the new check points?  and how did you do past exams when you haven't even done units 1 and 2?

[alchemy]

so your doing 1 and 2?  What do you mean you did the content and you bought the new check points?  and how did you do past exams when you haven't even done units 1 and 2?

I did the content (from the textbook) during orientation week. I'm just having a go at Checkpoints for practice and brushing up on things.
Long story short, I studied MM 1/2 in my spare time earlier this year, but am studying it only this year at school. I was sketchy on many topics so I created a question thread.