A force F = (3x + 4) newton displaces an object of mass 10 kg from x = 0 to x = 4m. If the speed of the object at x = 0 is 2ms-1, its speed at x = 4m will be ___m/s

Work done by the force isdW=fdxW=∫04 (3x+4)dx    =3x22+4x04=40JFrom work energy principle, work done = change in kinetic energy.    W=Δk=12mv2−u2    40=12×10×v2−22⇒v=23=3.46ms−1