In a pickup game of dorm shuffleboard, students crazed by final exams use a broom to propel a calculus book along the dorm hallway. If the 3.5 kg book is pushed from rest through a distance of 0.88 m by the horizontal 25 N force from the broom and then has a speed of 1.63 m/s, what is the coefficient of kinetic friction between the book and floor?

2 answers

Work done by broom = Kinetic energy increase + work done against fraction

Compute the friction work using that equation. Divide it by the distance moved to get the friction force. Use that to get the friction coefficient
m = 3.5kg
x = 0.88m
f = 25N
speed = 1.63m/s
coefficient of kinetic friction = ?
we know, fk=fnormal*coefficient of kinetic friction
where fk = kinetic frictional force
so, fk= mg*coefficient
fk=3.5*9.8*cefficient
a=?
so applying the equation
v^2=u^2+2ax
a= 1.1m/s^2
fnet=ma
so, ma=3.5*9.8*coefficient
cefficient= 0.11