SOLUTION: The distance required for a car to stop is directly proportional to the square of its velocity. If a car can stop in 112.5 meters at 15 kilometers per hour, how many meters are nee

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Question 65897: The distance required for a car to stop is directly proportional to the square of its velocity. If a car can stop in 112.5 meters at 15 kilometers per hour, how many meters are needed to stop at 25 kilometers per hour?
Answer Choices:
A) 250.75
B) 298.00
C) 312.50
D) 337.50
Found 2 solutions by checkley71, chitra:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
15^2/2=225/x=112.5
112.5x=225
x=225/112.5
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25^2/2=625/2=312.5 answer C)

Answer by chitra(359) About Me  (Show Source):
You can put this solution on YOUR website!
It is given that distance is directly proportional to the velocity square.

This is represented as:

d directly proportional to v%5E2

By data:
If the speed of the car is 15 km/hr then the distance required to stop the car is 112.5m.

If the speed of the car is 25 km/hr then the distance required will be equal to ?

Let that be equal to "x".

To calculate this we use the data which says:

d directly proportional to v%5E2

Hence,

112.5 m ==> 15%5E2km/hr


X m ==> 25%5E2km /hr


Let us cross multiply to find the distance "x"


Therefore,


x = %28112.5+%2A+25+%2A+25%29%2F%2815+%2A+15%29


x = %28112.5+%2A+625%29%2F%28225%29


x = (70312.5/225)

x = 312.5m

Hence, the car requires 312.5m to stop if the velocity is 25 km/hr


I hope the steps are clear.