Answer:
3 Newtons
Step-by-step explanation:
The work done by Kendall is given by:
![W=Fd](https://img.qammunity.org/2020/formulas/physics/high-school/d8vjw5oltzw7zvw8lsm9mtjiskvxowyao9.png)
where
F is the force
d is the displacement of the sofa
In this problem, we know
W = 30 Nm = 30 J
d = 10 m
So we can solve the formula for F to find the force used by Kendal:
![F=(W)/(d)=(30 J)/(10 m)=3 N](https://img.qammunity.org/2020/formulas/physics/middle-school/3qk9j2913xfzvobwrn1jw5ajaj5jhtfgdh.png)