If you are driving down a 10% grade, you will alway be 10% below where you would have been if you could have driven on flat ground from where you started. Suppose you descend to where you are 20 feet below your starting point. What concept does he "grade" relate to and how far would you have been from where you started if you had driven on flat ground? What is the math equation if any?
The concept that the "grade" relates to in this scenario is the slope or incline of the road. A 10% grade means that for every 100 units of horizontal distance you travel, you descend (or ascend) 10 units vertically.
To determine how far you would have been from where you started if you had driven on flat ground, we can use the fact that the grade reduces your position by 10% of the horizontal distance traveled. Let's assume you traveled a horizontal distance of x feet.
Since the grade is 10% or 0.1, you would descend (or ascend) 0.1x feet for every x feet traveled horizontally. Therefore, if you descended 20 feet, we can set up the equation as:
0.1x = 20
To find x, we can solve this equation. Dividing both sides by 0.1 gives:
x = 200
So, if you had driven on flat ground, you would have been 200 feet away from where you started since you traveled a horizontal distance of 200 feet.
Math equation: 0.1x = 20