The value $V$ of a certain automobile that is $t$ years old can be modeled by $V(t)=14,352(0\mathrm{.}78{)}^t.$ According to the model, when will the car be worth each of the following amounts?

$($a$)$ $$8000$

$($b$)$ $$6000$

$($c$)$ $$2000$

$($a$)$ The car will be worth $$8000$ after years.

$($Type an integer or a decimal rounded to the nearest tenth as needed$)$