How Does Velocity Impact Acceleration in Race Cars?

[karush]

A race car strarts from rest and travels east along a straight and level track.
For the firs $5.0s$ of the cars motion,
the eastward compent of the car's velocity,is given by
$v_x(t)=(0.930 m/s^3)t^2 $
What is acceleration of the car when $v_x=14.5$

ok my first step with this was

$$A=\frac{dv}{dt}=1.86t$$
if $v=14.5=0.933t^2$
then
$$t=3.94$$

so

$A(3.94)=1.86\cdot3.94=7.32 m/s^2$

 

[HallsofIvy]

You give, as the speed function, [math]0.930 t^2[/math], but when calculating the time when the speed is 14.5, you have [math]0.933t^2[/math]. Which is correct, 0.930 or 0.933?

 

[karush]

Hope this is better got lost in the W|A output

A race car strats from rest and travels east along a straight and level track.
For the first 5.0s of the cars motion,
the eastward compent of the car's velocity,is given by
$v_x(t)=(0.93 m/s^3)t^2$
a. What is acceleration of the car when $v_x=14.5
$$\begin{align*} \displaystyle
A&=\frac{dv}{dt}=1.86t\\
v&=14.5=0.93t^2\\
t&=3.94\\
A(3.94)&=1.86\cdot3.94=7.35 m/s^2
\end{align*}$$

I was ? on round off