I believe your answer should be C. Speed.
Answer:
Force=7.71KN in the opposite direction
Explanation:
Given the mass of the car(M)=1000Kg
The initial speed of the car(u)=100km/hr
we know that 1km/hr=5/18 m/sec
100km/hr=100*5/18 m/sec=27.77m/sec
the distance travelled before it stops (s)=50m
let the acceleration of the car be a
The final velocity of the car is 0.
we know that 

a=7.712m/
We know that F=Ma
F=1000* 7.712=7712N=7.71KN
Since the current is inversely propotional to its resistance, when the voltage is doubled the current will be one-half
Answer:
The appropriate answer is "0.9152 seconds".
Explanation:
The given values are:
Maximum speed,
v = 8.85 m/s
Acceleration,
u = 9.67 m/s²
Now,
⇒ 
By putting the values, we get
⇒ 
⇒ 
⇒