# Rearrange

• Sep 25th 2007, 09:44 PM
taurus
Rearrange
Hi jus a little help. Good someone show me the steps for rearranging the following equation in terms of 'u' please:

164 = u + 8 - 0.5 * 0.5 * (8^2)

?
• Sep 25th 2007, 09:49 PM
janvdl
Quote:

Originally Posted by taurus
Hi jus a little help. Good someone show me the steps for rearranging the following equation in terms of 'u' please:

164 = u + 8 - 0.5 * 0.5 * (8^2)

?

Let's simplify a bit first...

$164 = u + 8 - (0,5 \times 0,5 \times 64)$

$164 = u + 8 - 16$

$164 - 8 + 16 = u$

$164 + 8 = u$

$u = 172$

EDIT: This is my 5:):)th post
• Sep 25th 2007, 10:41 PM
taurus
got another one
i got another one im a bit confused on:
(to get u)

10 = 0.5 * 9.81 * ((40/u)^2)

now wat i tried was:

10 = 4.91 * ((40/u)^2) -------------------- (0.5 * 9.81)

then i got a bit confused there, do i square root it all or wat?
• Sep 25th 2007, 10:46 PM
janvdl
Quote:

Originally Posted by taurus
i got another one im a bit confused on:
(to get u)

10 = 0.5 * 9.81 * ((40/u)^2)

now wat i tried was:

10 = 4.91 * ((40/u)^2) -------------------- (0.5 * 9.81)

then i got a bit confused there, do i square root it all or wat?

$10 = 0,5 \times 9,81 \times ( \frac{40}{u} )^2$

$10 = 4,905 \times \frac{1600}{ u^2 }$

$\frac{1600}{ u^2 } = 2,04$

$\frac{1600}{2,04} = u^2$

$784,8 = u^2$

$u = 28,01$ (Nod)