When you push a 1.70 kg book resting on a tabletop it takes 2.60 N to start the book sliding. Once it is sliding, however, it takes only 1.50 N to keep the book moving with constant speed. What are the coefficients of static and kinetic friction between the book and the tabletop?
physics - Henry, Sunday, October 16, 2011 at 6:16pm
Wb = mg = 1.7kg * 9.8N/kg = 16.66N.
Fb = (16.66N,0deg) = Force of book..
Fp = 16.66sin(0) = 0 = Force parallel to table.
Fv = 16.66cos(0) = 16.66N. = Force perpendicular to table.
1. Fap - Ff = 0, Fap = Force applied.
2.60 - Ff = 0, Ff = Force of friction.
Ff = 2.60,
u*Fv = 2.60,
16.66u = 2.60,
u = 0.156. = Static coefficient of friction.
2. 1.5 - Ff = 0,
Ff = 1.5,
u*Fv = 1.50,
16.66u = 1.5,
u = 0.09 = Kinetic coefficient of friction.