Evaluate:

Given: **a=d/t**^{2 }and **d=rt+1/2at ^{2}**

Find the values of ** a** and

ManuelBautista2019 Oct 24, 2017

#1**+2 **

Hello Manuel,

Why is it that you give your own questions points but you almost never give the answerers any points?

Also,

Why is it that you always say please, which is very nice, but you never say thank you?

Melody Oct 24, 2017

#3**+3 **

Melody

I always say thank you to whoever answers my questions

but you don't see it because I always send the person a private message

Also, I forgot the give the others questioners points

And by the way, Thanks for the answer

ManuelBautista2019
Oct 24, 2017

#4**+1 **

You are welcome and if you send private messages that is really nice of you.

It is also nice and important that you thank people publicly because it sets an example for others.

If new people do not see anyone else saying thank you then they are more likely to think that they, for some bizarre reason they are not supposed to say thanks. People copy the behaviours of others. :)

Welcome to the forum by the way. I know you have been here for over a month but that still isn't all that long.

Melody
Oct 24, 2017

#2**+3 **

Evaluate:

Given: a=d/t2 and d=rt+1/2at2

Find the values of a and t when d=2 and r=3

\(Given: a=\frac{d}{t^2} \;\; and\;\;d=rt+\frac{1}{2}at^2\\\text{Find a and t when d=2 and r=3}\\~\\ a=\frac{2}{t^2}\;\;(1) \;\; and\;\;2=3t+\frac{1}{2}at^2\;\;(2)\\ at^2=2 \;\;\;(1b)\\ sub \;1b\;into\;2\\ 2=3t+\frac{1}{2}*2\\2=3t+1\\1=3t\\t=\frac{1}{3}\\ \text{sub back into (1)}\\ a=2\div\frac{1}{3^2}=2*9=18\\ so\;\;t=\frac{1}{3}\;\;and\;\;a=18 \)

Melody Oct 24, 2017