Download Basic Sliding Friction A04

HS Physics Wiki Quiz
Basic Sliding Friction
Question
A group of physics students try to push a giant 200 kg stack of physics books across the
floor.

If the students have to push with a force of 655 N before the books start to move, what
is the coefficient of static friction between the books and the floor?

Still pushing at 655 N, the students notice the books are now accelerating at 1.13
m/s2. What is the coefficient of kinetic friction?

If the students push harder will the books accelerate at a greater rate or will friction
increase to keep their acceleration steady?

The students are concerned because they are running faster and faster (as the
books accelerate). What force should they push with so that the books move at a
constant velocity?
Answer
Answer:
430 N.
They should push just as hard as the frictional force. That way, the two forces will cancel each other and
stop acceleration. That does not mean that it will stop!
So what is the frictional force?