You push a box along the floor against a constant force of friction. When you push with a horizontal force of 78 N the acceleration of the box is 0.46 m/s2; when you increase the force to 86 N the acceleration is 0.76 m/s2. (a) Find the mass of the box.

Question

You push a box along the floor against a constant force of friction. When you push with a horizontal force of 78 N the acceleration of the box is 0.46 m/s2; when you increase the force to 86 N the acceleration is 0.76 m/s2. (a) Find the mass of the box. 
(b) Find the coefficient of kinetic friction between the box and the floor.

bobpursley · Answer

78-mu(mass)g=mass*.46 86-mu(mass)g=mass*.76 subtract the first equation from the second 8=mass(.30) solve for mass. b. in either equation,put in mass, g, then solve for mu.