. Here's the correct solution:
According to the problem, the distance required for the car to stop is directly proportional to the square of its velocity. So, we can say:
D = kV^2
where D is the distance required to stop the car, V is the velocity of the car, and k is the constant of proportionality.
We are given that the car can stop in 1800 meters from a velocity of 30 kph. Therefore, we can write:
1800 = k * 30^2
Solving for k, we get:
k = 1800 / (30^2) = 2/3
Now, we can use this value of k to find the distance required for the car to stop at 28 kph:
D = (2/3) * 28^2 = 627.56 meters
Therefore, the required distance for the car to stop at 28 kph is approximately 627.56 meters.