You push a box along the floor against a constant force of friction. When you push with a horizontal force of 75 N the acceleration of the box is 0.55 m/s2; when you increase the force to 85 N the acceleration is 0.78 m/s2.

Question

(a) Find the mass of the box. kg

(b) Find the coefficient of kinetic friction between the box and the floor.

Answer 1

Net force= m*a
75-friction=m*.55
85-friction=m*.78
subtract the first equation from the second

10=m(.23)
m= 10/.23
then solve for friction in either equation, finally, mu=frictionforce/mg

Answer 2

thank you