Melody

Hi guest and Solveit,
 

A boat takes off from the dock at 2.5 m/s and speeds up at 4.2 m/s2 for 6.0 s. How far has the boat traveled? Round your answer to the nearest whole number.

Your formula is incorrect guest  .    The one you are thinking of is   v=u+at

u=2.5m/s,     a=4.2m/s^2      t=6s,      find s

The one you need is

\(s=ut+0.5at^2\\ s=2.5*6+\frac{1}{2}*4.2*36\\ s=15+2.1*36\\ s=90.6\; metres.\)

When I was at school I did both maths and physics.  

Now in physics I used the physics formulas    BUT     in maths ir was compulsory to use calculus!

So now I will do it with calculus.

\(x\; is \;displacement,\;\;\\\frac{dx}{dt}\;\;is \;velocity\;\;\;\\\frac{d^2x}{dt^2}\;\;is \;acceleration\;\;\;and\;\\t\;is\;time.\\ \)

\(\frac{d^2x}{dt^2}=4.2\\ \frac{dx}{dt}=4.2t+c_1\\ when\;t=0\;\;\frac{dx}{dt}=2.5\\ \quad sub\; in\\ 2.5=4.2*0+c_1\\ c_1=2.5\\ \frac{dx}{dt}=4.2t+2.5\\ x=\frac{4.2t^2}{2}+2.5t+c_2\\ \mbox{When t=0, x=0 so }c_2=0\\ x=\frac{4.2t^2}{2}+2.5t\\ When \; t=6\\ x=2.1*6^2+2.5*6\\ x=90.6\;metres \)

That is how you do it using calculus    

Thanks Guest :))

x-y=3 then x^3-y^3-9xy =?

This is fascinating.  Look at this weird graph!

 P(t)=10,478,756(1+.0123)10

10,478,756*(1+.0123)^10 = 11841373.9498238932804773227003680901783250768644

I used the forum calculator. ://

Thanks Chris and guest,

 Hi PurplePotato, you have a fabulous username!  Welcome to the forum :)

Yes Nauseated, pat, pat, I understand that your response would have taken major effort....

It was a response, but it was not an answer to the actual question so it did not qualify for an answer distinction nomination. :/

I am really sorry but I cannot allow every mutt who leaves his mark to be rewarded now can I.   

Never mind, pat,pat, pat,  there is some more cat food in the fridge for you.  That will make you feel better.   Pat, pat, pat.  :)

Thanks guest.  :)

Are you happy now Katie or would you like more help ? :/

Just google it.  

This forum is best used for mathematics things that cannot be googled easily!

In other words you are wasting our time.

Hey Chris, do I have to answer my own question :/  LOL

I wonder how easy it would be for either of us if the question were harder.

Say 3 had to be seperated and there were 25 others to go into the line as well.

How hard is this one?

It is too late for me to think about it now.  Maybe you might like to consider it though :)

This is what I reckon.

There are 25! ways the non trouble makers can be put in a line. 

Then there are 26 spots where the other 3 can be slipped in so that is    26P3 = 26*25*24 = 15600

So there would be  15600*25! ways.

And this is about 2.4*10^(29)   and that is a HUGE number of ways :))

Fri 15/1/16

1)  Jokes on the forum,  thanks Olivia3.14.... , Hayley and CPhill    

     http://web2.0calc.com/questions/math_75574

2)  The humour in this one appealed to me,  Thanks guest Hayley and Solveit  

     http://web2.0calc.com/questions/math_11311

3)  Chemistry        Thanks Nauseated and guest.

     http://web2.0calc.com/questions/chemistry-math_2

4)  Simultaneous equations - with a difference with a weird graph.  ://     Thanks guest and Melody.

     https://web2.0calc.com/questions/problem_76364

5)  Motion problem using formula OR calculus     

     http://web2.0calc.com/questions/65165#r5

6)  Co-ordinate geometry reflection.  Cool graph too     Thanks CPhill

     http://web2.0calc.com/questions/reflection-of-conic-with-line

7)  Finding zeros of a polynomial of degree 3   Thanks guest and CPhill

     http://web2.0calc.com/questions/math_85056

8)  Matrices  Thanks Heureka and CPhill

     http://web2.0calc.com/questions/matrix-pt-3

9)  Find the next terms in the sequence       Heureka's brilliance continues from yesterday :)

     http://web2.0calc.com/questions/sequence_3#r5

10)  A downloadable calculator with a DMS button.  Thanks guest - Much appreciated

                  (continued from yesterday)

      http://web2.0calc.com/questions/i-need-that-dms-button

@@ What is Happening?  [Wrap4]   Thurs 14/1/16   Sydney,  Australia Time 11:07 pm   ♪ ♫

Hi everyone,

Great answers today were provided by Solveit, CPhill, Hayley1, Admin, calmmylife, Heureka, gibsonj338, xvxvxv and GenericUserNameHere.    Thank you      

Interest Posts: 

If you ask or answer an interesting question, you can private message the address to me (with copy and paste) and I will include it.  Of course only members are able to do this.  I quite likely will not see it if you do not show me.

1)  How long will it take.  I like these problems.  Thanks Solviet, Hayley, Melody Guest and CPhill.