Inelastic Collision Using Distance to Figure Velocity

[Luudy]

For my intro to physics class, we have to do a project known as Phylm, in which we analyze a scene from a movie that utilizes physics in some way and then determine, based on our findings, whether the situation is viable or not. I'm using the scene from V for Vendetta in which V throws a pair of knives and knocks two bodyguards back approximately 1.52 Meters. My question is, using the data below, how do I figure out the velocity of the knife, and then how much force it would take a man to throw the knife at that velocity? The collision is perfectly inelastic.

Weight of knife (a): .567 Kg
Weight of bodyguard: 104.8 Kg
Distance bodyguard travels after being hit: 1.52 m
Initial velocity of bodyguard: 0 m/s²

 

[Modulated]

I'm afraid you're going to have to give it a bit of a go yourself before anyone leaps to your assistance. (It might also be a good idea to use the forum's homework template.)

 

[Luudy]

I've actually got it now, chief. I just figured out how much the film had been slowed down from normal, which was down by 1/4, and then figured out the bodyguard's final velocity based on how long it took him to fall backwards the 1.52 meters. If there's a better way to do it, though, it would be much appreciated. I feel like I had to guess about too many variables this way.