Here's a Question! - A Basketball Rolls Off a Table
A basketball rolls across a horizontal table. It rolls off the edge and falls to the floor. What path does the basketball take as it falls to the floor?
Announcer: Frostbite Theater presents... Cold Cuts! No baloney!
Joanna and Steve: Just science!
Joanna: Hi! I'm Joanna!
Steve: And I'm Steve!
Joanna: Here's a question for you...
Steve: A basketball rolls across a horizontal table.
Joanna: It rolls off the edge and falls to the floor.
Steve: What path does the basketball take as it falls to the floor?
Joanna: Does it fall straight down?
Steve: Does it go across for a bit and then fall straight down?
Joanna: Does it fall in a straight, diagonal line?
Steve: Or, does it fall on a curved path?
Joanna: Pause the video now if you'd like to think it over before we show you what happens.
Since gravity is only acting vertically, it's convenient if we split the basketball's motion into horizontal and vertical components.
Steve: The basketball has some horizontal velocity as it rolls across the table. Gravity, which is acting at perpendicular to it, can't change it, even when the ball falls off the table. If we ignore air resistance and friction, the ball's horizontal velocity does not change.
Joanna: What does change is the basketball's vertical velocity. Once the ball reaches the end of the table, gravity accelerates the ball downward. And, again, if we ignore air resistance, this acceleration remains constant until the ball hits the floor.
Steve: A constant horizontal velocity paired with an increasing vertical velocity results in a curved path. A parabola, if everything works out correctly.
Joanna: Thanks for watching. I hope you'll join us again soon for another question!
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