To solve this problem it is necessary to apply the concepts related to the conservation of the Momentum describing the inelastic collision of two bodies. By definition the collision between the two bodies is given as:

Where,
= Mass of each object
= Initial Velocity of Each object
= Final Velocity
Our values are given as




Replacing we have that



Therefore the the velocity of the 3220 kg car before the collision was 0.8224m/s
Answer:
Voltage-gated calcium ion channels open, and calcium ions diffuse into the cell
I think it's D because sunlight is a solar system