Question

I am so lost, please help

Answer 1

Answer:

$u=\frac{9}{t}-\frac{1}{2} a t$

Step-by-step explanation:

Step 1: Given equation: $9=\frac{1}{2} a t^{2}+u t$

To get u, by subtraction equality property subtract both sides of the equation by  $\frac{1}{2} a t^{2}$.

$\Rightarrow 9-\frac{1}{2} a t^{2}=\frac{1}{2} a t^{2}+u t-\frac{1}{2} a t^{2}$  

$\Rightarrow 9-\frac{1}{2} a t^{2}=u t$  

Step 2: By division equality property, divide both sides of the equation by t.

$\Rightarrow \frac{9-\frac{1}{2} a t^{2}}{t}=\frac{u t}{t}$

$\Rightarrow \frac{9}{t}-\frac{1}{2} a t=u$  

Therefore, $u=\frac{9}{t}-\frac{1}{2} a t$.

So, in Emily’s physics class, she got $u=\frac{9}{t}-\frac{1}{2} a t$.