Answer
$v$ is continuous at $t=20.$
There was no abrupt change.
Work Step by Step
As found in part (a), the one-sided limits exist and are equal to $60$.
The function value at $t=20$ is
$\quad v(20)=174(20)-3420=60,$
so $v$ is continuous at $t=20.$
Thus, there was no abrupt change.
