The trick, then, is to combine a quantity expressed in these terms with a quantity expressed in meters per second and a quantity expressed in kilograms, and wind up with a quantity expressed solely in meters. To do that, you need to get rid of the “kg” and the “s” by canceling them out. Start by canceling out the “kg”:
Now you need to cancel out the “s2” in the denominator. Let’s divide by the square of our “m/s” quantity:
There you have it. You didn’t need to use a single formula to get the answer. You just had to be aware of the terms in which your answer needed to be expressed, and manipulate the quantities you were given in the question.
Word to the wise: don’t use this method unless you’re absolutely stumped. It can backfire, and is of course no substitute for careful reasoning
