00:01
All right, so let's say we have a vertical spring like this with a block dropped from a height of 0 .45 meters.
00:10
And the mass of this should be a block is two kilograms.
00:16
And so we want to find what is the speed of it, or sorry, what is the force in the spring when it reaches equilibrium position? so the equilibrium position, we'll call this x is just going to be mg over k.
00:28
Right and so the total energy of the system should equal m gh because that's the initial energy and so the final energy at this point is going to be like one -half k x squared where x is what we have here plus one -half mv squared but at we're just looking at the force for this part so the force is going to be k x this or course is just equal to m g so this will just be 19 .6 newtons.
01:05
Then we want to find the maximum velocity at equilibrium.
01:08
So basically what we'll have here is 1 half, our mgh equals 1⁄2x squared plus 1⁄2mv squared.
01:18
And so if we can multiply by 2 everywhere and divide by the mass, we'll have 2gh minus k over mx squared.
01:28
Take the square root of that.
01:29
That should be our velocity...