If you want to get faster, more explosive aka quicker you have to increase Mass or Force into the ground (weight/Load) and Acceleration (Speed).  Force = Mass x Acceleration (F=MxA) or Acceleration = Velocity over Time (A=V/T).  Simply if you increase load or weight (mass) on a squat or vertical jump you have the potential to be faster.  In addition, if you can improve speed (acceleration) you also have the potential to be quicker.  Or if you improve the ability to apply more