Answer:
The value is
![\mu = 0.76](https://img.qammunity.org/2021/formulas/physics/college/317zamqm6f9ei6ky8ajpo98xm6yr1ie2fr.png)
Step-by-step explanation:
From the question we are told that
The acceleration is
![a = 7.4 \ m /s^2](https://img.qammunity.org/2021/formulas/physics/college/5vzlm2cafe1qbkqvmz1a04byf1qq8vlz93.png)
Generally the force by which the truck bed (truck) is moving with is mathematically represented as
![F = ma](https://img.qammunity.org/2021/formulas/physics/college/66xnbespu5t7glxyysllcsc44jbw8uxpg7.png)
Now for the truck cabinet to slip from the truck bed then the frictional force between the truck cabinet is equal the force by which the the truck bed is moving with that is
![F_f = F](https://img.qammunity.org/2021/formulas/physics/college/kf4jx7e5mx6o271447d6ozhwibj1dnyx6r.png)
Here
is the frictional force which is mathematically represented as
![F_f = \mu * m * g](https://img.qammunity.org/2021/formulas/physics/college/h4z3oa9pzc9nm865edbli8ppd7ciqvexud.png)
substituting into above equation
![\mu * m * g = ma](https://img.qammunity.org/2021/formulas/physics/college/kg4f8aoo6fgsaeaubohhd07r37ukx34pj5.png)
=>
![\mu = (a)/(g)](https://img.qammunity.org/2021/formulas/physics/college/k07l3xk6sl7lo2nfvt2ebb0xmvbk6v53oh.png)
substituting values
![\mu = ( 7.4 )/( 9.8)](https://img.qammunity.org/2021/formulas/physics/college/9wy8cz24gnbfwom488yl5d65y85beenvx5.png)
![\mu = 0.76](https://img.qammunity.org/2021/formulas/physics/college/317zamqm6f9ei6ky8ajpo98xm6yr1ie2fr.png)