Answer:
[tex]1.4\cdot 10^5 N[/tex]
Explanation:
First of all, we can find the work done as follows:
[tex]W=Pt[/tex]
where P is the power and t is the time taken. In this problem, [tex]P=7.0\cdot 10^4 W[/tex] and [tex]t=40 s[/tex], so the work done is
[tex]W=Pt=(7.0\cdot 10^4 W)(40 s)=2.8\cdot 10^6 J[/tex]
The work done is equal to the force applied F times the displacement d:
[tex]W=Fd[/tex]
since we know d=20.0 meters, we can re-arrange the equation to find the force exerted:
[tex]F=\frac{W}{d}=\frac{2.8\cdot 10^6 J}{20.0 m}=1.4\cdot 10^5 N[/tex]
