# Friction and the Coefficents of Friction question

## Homework Statement

so my question is; A horizontal force of 110 N (forward) is required to get a 35 kg box to start moving across a floor, Calculate the coefficent of static friction.
The equations i have been given are Ff=uFn
But I have just started this unit and am so confused. I don't even know where to start.

## The Attempt at a Solution

First, draw a free body diagram for the box - include all forces.
It may help to list what you know and what need to find (organize the info outside of the question).

Floor is horizantal so normal force equals gravitational force. To break frictional force, applied force must equal it.

1. Three blocks are tied to each other with
two pieces of string, one of which
passes over a frictionless pulley, as
shown. The coefficient of friction
between each block and the surface on
which it slides is 0.2. Just as the
system starts to move, the 3 kg and
6 kg blocks are each one metre away
from the pulley.

1.1Determine the tension in each of the strings.
1.2 How long before one of the blocks jams the pulley?

#### Attachments

• Diagram....jpg
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