In this video we are going to calculate the work required to accelerate the now-check that initials address, so at velocity 0 to velocity final of we. So let's start by writing down what we know. We know there's a link between the final velocity and initials, so we know from kinematics. Now that the final velocity is the initial velocity, the acceleration times time, we also know the displacement, delta s is the initial velocity times time plus 1.5 times the acceleration times time squared. Then what else do we know? We know from Newton's laws of motions from kinematics, we have some f-met, this and a-met, and finally from the energy chapter we have the mechanic work, work is force times displacement times with the cosine of the angle. From kinematics, we actually know way more. We have another equation that I forgot to write, that is the final square is the initials plus 2A, and j-d displacement. Now why don't you just write that one down, because looking at our work equations, we need to find a way to calculate the force, so that we can do from dynamics. We need a way to calculate s, distance it will take us to accelerate the object to our final speed, and I could calculate it with my first three equations, but often have time in there, we have no information about time, so that one here could be an interesting equation, and we could use it to calculate our distance. So let's do that, let's start with force. So f-met is an a, I am pulling that way, I am accelerating that way, so my estimation with my f-net, which is that only force here that I have, and forward directions and a, then my displacement, now taking my equation from kinematics, so let's call this equation 2. My final square is v-nissue, which is 0, plus 2 plus a, minus delta s, so we get delta s is v-final, which is v, so we square over 2A. But the angle between the direction of the travel and the force, the angle is 0, so let's combine, work, it's the force, so mass times acceleration, times displacement, so times v square over 2A, and then times cosine of 0. Now cosine of 0 is 1, displacement goes away, and when I rewrote it, I get m is square over 2. Now maybe that does look similar to a familiar yet, but if I rewrote it like this, have you seen this before? It's of course you have, that's the formula for kinematics. When the kinematics is 1,5 and v square, and it has to be that formula, because it has to be adjusted, if you think back at final energy is initial energy plus 4, so we added the word of 1,5 and v square. Initially we have a lot of zeros, so no kinematics is well, and final was the generator, well of kinematics is final, so we have just proved the formula for kinematics, that it must be 1,5 and v square.