9.8 ms^-2 is acceleration
I believe d all of the above
Answer:

West
Explanation:
m = Mass of car = 
t = Time = 9 seconds
u = Initial velocity = 30 m/s
v = Final velocity = 0
Impulse is given by

The magnitude of the total impulse applied to the car to bring it to rest is
.
The direction is towards west as the sign is negative.
Answer:
To create an electric potential difference between the ends of the conductor.
Explanation:
For current to flow, there must exist an electric potential difference between the ends of the conductor. This PD is provided by the electromotive force stored within the battery. Unless there is a connection between the terminals no PD will exist between the terminals.