Respuesta :
Answer:
The speed of Susan is 2.37 m/s
Explanation:
To visualize better this problem, we need to draw a free body diagram.
the work is defined as:
[tex]W=F*d*cos(\theta)[/tex]
here we have the work done by Paul and the friction force, so:
[tex]W_p=F_p*d*cos(0)\\F_p=30N*cos(30^o)=26N\\W_p=26*3*(1)=78J[/tex]
[tex]W_f=F_f*d*cos(180)\\F_f=\µ*(10*9.8-30N*sin(30^o))=16.6N\\W_p=16.6*3*(-1)=50J[/tex]
Now the change of energy is:
[tex]W_p-W_f=\frac{1}{2}m*v^2\\v=\sqrt{\frac{2(78J-50J)}{10kg}}\\v=2.37m/s[/tex]

Answer: speed= 1.95866m/s ~= 2.0 m/s
Explanation: check attachment for explanation
