Question

Find the work done by a force (in newton) Fx = 5x -4 when this force acts on a particle that moves from x= 1m to x= 3m.

Answer 1

Work Done = $\int\limits^a_b{F} \, dx$, where a= initial position and b = final position.

Therefore, W = $\int\limits^3_1 {(5x-4)} \, dx$
                       =$[(5/2)x^{2} - 4x]\left \{ {{3} \atop {1}} \right.$
                       =[{(5/2)(9) - (4)(3)} - {(5/2)(1) - (4)(1)}]
                       
 Upon solving, we get Work Done = 12J