Among the scenarios listed, the one that would use a quadratic equation to solve is:
A coach models the trajectory of a ball to find out how high the player is kicking the ball.
This scenario involves the motion of a projectile, which is typically described by a quadratic equation due to the parabolic trajectory caused by gravity.
The other scenarios do not involve quadratic equations:
- A child placing a quarter into a piggy bank every week describes a linear situation as the total money increases by a fixed amount weekly.
- An accountant models the growth of a savings account that doubles every month describes exponential growth, which is modeled by exponential functions rather than quadratic equations.
- The trajectory of a balloon that rises 2 feet per second describes linear motion, as the height increases at a constant rate.