The formula is CaCl2 as you need two Cl ions in order to combine with one Ca ion in order to form a neutral compound i.e. You need to have the same amount of charges therefore you have two Cl ions which have -1 charges for one +2 Ca ion.
Hope this helps :).
Answer:
Explanation:
Velocity is at its greatest when kinetic energy is at its max which is when all the ball's energy has been transformed from potential energy to kinetic energy which is at the lowest point in its travels (assuming the ball is rolling down a ramp). You have no picture here so this answer is a general one, not a specific one.
A run though an open field during a thunderstorm is the answer
It can be noted that the directions west and north are perpendicular to each other. hence we can use the right angle formula for calculating total distance in these directions. Also South is just negative north. This technique is called euclidean distance norm. It is the basis of Cartesian coordinate system.
Total distance = 3.22 N + 4.75 W +1.90 S
= 1.32 N + 4.75 W
D = 
D = 4.93 Km
direction = atan(N/W) = 15.53 deg north of west