Question

A 17 kg box experiences an applied force of +175 N and a force of friction of -125 N. While experiencing these unbalanced forces, the box travels a total of 15.0 meters in 5.25 seconds.

Calculate the power developed by the unbalanced forces to move the box.



A
44.1 watts
B
143 watts
C
263 watts
D
750 watts

Answer 1

Answer: (b)

Step-by-step explanation:

Given

Mass of box
`m=17\ kg`

Applied force
`F=175\ N`

Friction force
`f=-125\ N`

Box travels a distance of
`s=15\ m`

time taken
`t=5.25\ s`

Net unbalanced force
`F_(net)=175-125=50\ N`

Work done by the unbalanced force

`\Rightarrow W=F_(un)\cdot s\\\Rightarrow W=50* 15\\\Rightarrow W=750\ N`

Power developed by unbalanced force

`\Rightarrow P=(W)/(t)\\\\\Rightarrow P=(750)/(5.25)\\\\\Rightarrow P=142.85\approx 1423\ W`

Thus, option (b) is correct.