Answer:
Work done = 600 J
Power used = 60 W
Explanation:
Given:
Force acting on the box is, ![F=20\ N](https://tex.z-dn.net/?f=F%3D20%5C%20N)
Displacement of the box is, ![S=30\ m](https://tex.z-dn.net/?f=S%3D30%5C%20m)
Time taken for the work, ![t=10\ s](https://tex.z-dn.net/?f=t%3D10%5C%20s)
Now, we know that, work is said to be done by a force only when there is displacement caused by the force in its direction.
Here, the force acting on the box causes a displacement of 30 m in its direction. So, work done is equal to the product of force and displacement caused.
Therefore, work done on the box is given as:
![Work=Force\times Displacement\\Work=F\times S\\Work=(20\ N)\times (30\ m)\\Work=600\ J](https://tex.z-dn.net/?f=Work%3DForce%5Ctimes%20Displacement%5C%5CWork%3DF%5Ctimes%20S%5C%5CWork%3D%2820%5C%20N%29%5Ctimes%20%2830%5C%20m%29%5C%5CWork%3D600%5C%20J)
Therefore, the work done is 600 J.
Now, we know that, power is given as work done per unit time.
So, power used is given as:
![Power=\frac{Work}{Time}\\\\Power=\frac{600\ J}{10\ s}\\\\Power=60\ W](https://tex.z-dn.net/?f=Power%3D%5Cfrac%7BWork%7D%7BTime%7D%5C%5C%5C%5CPower%3D%5Cfrac%7B600%5C%20J%7D%7B10%5C%20s%7D%5C%5C%5C%5CPower%3D60%5C%20W)
Therefore, the power used is 60 W.