GMAT Practice Question: x = \frac{1}{6} gt^2 In the formula shown, if g is a constant and x=-6 when t=2...
Question
x = \frac{1}{6} gt^2 In the formula shown, if g is a constant and x=-6 when t=2, what is the value of x when t= 4?
- -24
- -20
- -15
- 20
- 24
Topics: linear equations, function variable substitution
Solution
Step 1
We let x be the displacement, t be the time, and g be the constant of proportionality in the given formula.
x = \frac{1}{6} g t^2
Step 2
We substitute x = -6 and t = 2 into the formula and solve for g.
-6 = \frac{1}{6} g \times 2^2 = \frac{1}{6} g \times 4 = \frac{4}{6} g g = -6 \times \frac{6}{4} = -9
Step 3
We substitute g = -9 and t = 4 into the formula to calculate x.
x = \frac{1}{6} \times (-9) \times 4^2 = \frac{1}{6} \times (-9) \times 16 = \frac{-144}{6} = -24
Answer
The value of x is -24.
