http://www.ck12.org Chapter 4. Newton’s Laws
- The physics professor holds an eraser up against a wall by pushing it directly against the wall with a completely
horizontal force of 20 N. The eraser has a mass of 0.5 kg. The wall has coefficients of frictionμS= 0 .8 and
μK= 0. 6.
a. Draw a free body diagram for the eraser.
b. What is the normal forceFNacting on the eraser?
c. What is the frictional forceFSequal to?
d. What is the maximum mass m the eraser could have and still not fall down?
e. What would happen if the wall and eraser were both frictionless?- A tractor of mass 580 kg accelerates up a 10◦incline from rest to a speed of 10 m/s in 4 s. For all of answers
below, provide a magnitude and a direction.