#### Answer

Decrease

#### Work Step by Step

In Problem 15a we used
$L = – \frac{v² – v₀²}{2g sin θ}$
to find the minimum length of the ramp. If we were to decrease the speed $v₀$ of the truck, the numerator of this expression would be smaller (since the final speed $v$ = 0), and therefore the value of L would decrease as well.