In an action-adventure film, the hero is supposed to throw a grenade from his car, which is going 90.0 km/h, to his enemy's car, which is going 127 km/h. The enemy's car is 15.6 m in front of the hero's when he lets go of the grenade. If the hero throws the grenade so its initial velocity relative to him is at an angle of 45 degrees above the horizontal, what should the magnitude of the initial velocity be? The cars are both traveling in the same direction on a level road. You can ignore air resistance. I've bee reading this problem over and over again, and don't really know how to start. Since I am supposed to find initial velocity, I need the vertical and horizontal component. But from the question, I don't know how to find the horizontal component. Can someone please lead me in the right direction?