A box sits at the top of an unloading ramp. As the ramp is gradually tilted down from horizontal, the box will eventually start to slide down the ramp; the ramp then stops futher tilting and is held at this angle. Considering friction realistically, once the box starts to slide it is most- likely to then:
a) come to rest in a short distance due to the difference between static and kinetic.
b) continue to slide with increasing acceleration
c) Continue to slide at a constant speed because of friction, and the ramp tilt has stopped increasing.
d) Continuesto slide at a speed increasing with constant acceleration.