vec$(v{)}_i=($:$7\mathrm{.}4600,0,0$:$)\frac{m}{s}$

You are correct.

Your receipt no$.$ is $149-7429$

Previous Tries ${?}_{(})$

$($c$)$ At what time does the script stop running?

$t_f=0\mathrm{.}2000s$

You are correct.

Your receipt no$.$ is $149-8814$

Previous Tries ${?}_{(})$

$($d$)$ What is the momentum of the fan cart when the script stops running?

vec$(p{)}_f=($:$,$:$)kg**\frac{m}{s}$