- #1

Arquon

- 22

- 1

## Homework Statement

Box B is on top of box A. Box A has a mass of 1 kg, B has 0.3 kg. Coefficient of friction between ground and box A is 0.5, between box A and B : 0.75. With what maximum force can I pull box A without box B sliding back ?

m

_{1}= 1 kg

m

_{2}= 0.3 kg

u

_{1}= 0.5

u

_{2}= 0.75

## Homework Equations

F

_{fr}= umg

F = ma

## The Attempt at a Solution

I got that the force of friction between box A and ground is 6.5 N ( (m

_{1}+ m

_{2})u

_{1}g )

Between box A and B friction is 2.25 N. ( m

_{2}u

_{2}g )

So the total force of friction box A receives is 8.75 N. But I can't work out what is the maximum force with which I can pull box A without having box B falling off.