Melody

I am going to add this as an interest question so I thought I would comment a little further.

The vertical axis is m/s   the horizontal axis is seconds.

When you multiply these together the seconds cancel out and you are left with metres which is distance.

When you find the area of a rectangle it might be metres * metres so the units will be m^2

When you find the area under these lines the units are  m/s and seconds so the resultant unit is metres.

That is why you can find the distance travelled by finding the area under the curve.

If you have any comments or questions please post here. This is a really interesting and important concept.

Anonymous who has just joined up and is now AlexM has asked me to look over his answer.   

Hi Alex, I will look at your answer now.  I have copied it here so I can look and give feedback  both at the same time.   

let's start with cracking the two problems that already have an answer so we can understand how to solve0,5s + 3t. 

2s - 2 = 7

2s - 2 = 7 is an expression that says "the value of 2s minus 2 equals 7". That must mean that the original value of 2s was9, because 7 plus 2 is 9.

That must mean that 1s equals 4.5, because 2s equals 9.     GOOD

 3s + 5t = 10

We then move on to the next problem, 3s + 5t = 10. We know that 1s equals 4.5, so 3s must equal 4.5 * 3 = 13.5. Wait a second, 13.5 is above 10! What is this!? Well, 5t must be a negative value, with a total value of (-3.5). We use brackets to make it easier to read negative values. It's easy then! 13.5 + (-3.5) = 10! Actually, not as easy as someone may think, negative numbers involve in a bunch of pesky rules, that's why the answer is 10 and not 17. I recommend you to read about said rules in case you already haven't.

So, 5t equals (-3.5). How much is 1t? Let's simply just take (-3.5) and divide it by 5, like this: (-3.5) / 5 = (-0.7). 1t equals(-0.7).         GOOD

0.5s + 3t = ?

We now know that 1s equals 4.5 and that 1t equals (-0.7).

0.5s is half of the value of 1s. 0.5s = 4.5 / 2 = 2.25.

3t = (-0.7) * 3 = (-2.1).

 A simple, readable, version of the problem would then be 2.25 + (-0.7).

2.25 + (-2.1) = 0.15

 Finally, we have our answer, 0.5s + 3t = 0.15.       (YES this is the sames as CPhill's answer.)

 You have answered well Alex,  thank you.  

If you live near me ill tutor you. Otherwise we'll all help you out for free on the forum.

We are so lucky that we have you and your sister protecting Camelot.  You do a wonderful job.

Thanks so much.    

Declaration by the order of 

Queen Guinevere.

Not quite Dragon - I am wondering if the calc can handle different bases.  That is what the question really was.

@@ End of Day Wrap     Fri 26/9/14     Sydney, Australia    Time 12:01 am    (Really Sat morning)  ♬  

My goodness - I had no idea it was that late.  It's  been a long day.  No wonder I am tired.  

Hi everyone,

The forum has been rediculously busy.  Fortunately Geno3141 joined us as a power answerer.  I hope you stick around for a while Geno.  We need you! LOL.  Talking about power answerers, someone should fill me in on how Aziz is doing these days.  If you talk to him please pass on my best wishes.  

Of couse we have lots of great answerers.  Here you all are: Geno3141, CPhill, Rosala, Honga, Alan, Coolkille98, DragonSlayer554, Reaper, Quinn, Heureka, NinjaDevo and Kelseymcnamara.  Thanks everyone. 

@  I would like to remind everyone that the forum calculator has atan not tan^-1 .  This needs to be explained to people.  

@ If people ask about the fraction button please direct them to the sticky topic "How do I type in Fractions"  You can give them other info as well if you want to.

@ There are many great teaching sites on the web like mathsisfun etc.  Make good use of these references.  They often explain things better than we can.  

Now for the interest posts, I've pulled out about a hundred, 14 to be more precise.  Oh well, here they are:

1) What does this question mean?  (thanks Quinn - is Quinn correct?)

Sat 27/9/14

1) Rosala's funnies   (Thanks Rosala)

You are very welcome  

I don't understand.  I didn't take 15.  It was -20 m/s      

So mine is wrong?  I will admit I did not think about it very hard but i thought it would be ok.