A machine pushes a 2100kg block from rest to a speed of v, doing 3900 J of work. During this time the car moves 10 meters. Neglecting friction between the floor and the block, what is v? Work=3900J d=10 meters m=2100kg KE=1/2 x m x v^2 3900=1/2 x 2100 x v ^2 v^2= 3900 x 2 / 2100 v = 1.93. This is how I approached the problem but I'm not sure if it's right. I'm not sure if 3900 J's given equal the kinetic energy even though I set it equal to the KE. Can someone let me know if this is right? Thanks.