Bonus Question5 point A constant force F 2i8j moves an objec

Bonus Question(5 point): A constant force F 2i+8j moves an object along a straight line from the point (2,5) to the point (11,13). Find the work done if the distance is measured in feet and the force is measured in pounds. Good Luck

Solution

Ans: We know that differential of work is equal to the dot product of force and displacement, that is

dw = F.dr

Here dr = final point - initial point = (11,13)-(2,5) = 9i+8j

So, dw = (2i+8j). (9i+8j) = 18+64 = 82 pound feet.

1 foot pound = 1.355 joules. So 82 foot pound = 82 × 1.355 = 111.11 Joule.