Answer:
The acceleration is: 
Explanation:
Given
--- The initial velocity
--- time
-- The final velocity
Required
Determine the acceleration
To do this, we make use of the first equation of motion

We used negative because the car was coming to stop.
This gives:


Collect like terms

Solve for a


im pretty sute the answer would be number 4.
mark brainliest :)
Answer:
Result of the formation of positive and negative ions.
Answer:
lithium=atomic no.=3
Explanation:
-1 charge on lithium means one electron has added to it .Thus,
Li-1=no. of electrons=3+1=4
Is to find the problem to the investigation