In an experiment a student uses a force to set an object in motion along a wooden plank and observes the distance the object
travels before stopping. He then uses grease to lubricate the surface of the plank. When setting the object in motion using the
same amount of force along the greased plank, he observes that the object travels a greater distance before stopping. Why does
this happen?
A)
The grease makes the surface of the plank frictionless.
B)
The grease increases the contact between the object and the plank.
The grease prevents the object from touching the surface of the plank.
Eliminate
D)
The grease reduces the coefficient of friction between the object and the
plank.