Answer:
[tex]m=35.58 kg[/tex]
Explanation:
Using the first Newton's equation
[tex]\Sum F_{T}=F-mgsin(25)-\mu mgcos(25)=0[/tex]
We just need to solve it for m:
[tex]m=\frac{F}{g(sin(25)+\mu cos(25))}[/tex]
[tex]m=\frac{350}{9.81(sin(25)+0.64cos(25))}[/tex]
[tex]m=35.58 kg[/tex]
I hope it helps you!