Answer: (b)
Explanation:
Given
Mass of box [tex]m=17\ kg[/tex]
Applied force [tex]F=175\ N[/tex]
Friction force [tex]f=-125\ N[/tex]
Box travels a distance of [tex]s=15\ m[/tex]
time taken [tex]t=5.25\ s[/tex]
Net unbalanced force [tex]F_{net}=175-125=50\ N[/tex]
Work done by the unbalanced force
[tex]\Rightarrow W=F_{un}\cdot s\\\Rightarrow W=50\times 15\\\Rightarrow W=750\ N[/tex]
Power developed by unbalanced force
[tex]\Rightarrow P=\dfrac{W}{t}\\\\\Rightarrow P=\dfrac{750}{5.25}\\\\\Rightarrow P=142.85\approx 1423\ W[/tex]
Thus, option (b) is correct.
