Lecture 2 - Falling Balls and Gravity Flashcards
What are the stages when you drop a ball?
Begins at rests, soon acquires a considerable downward speed, covers more and more distance each second.
What are the stages when you toss a ball ?
The ball’s velocity starts upward but increases downward, altitude increases at slower and slower rate, position and velocity are momentarily at zero/still, ball moves downward like a dropped ball.
True or False: Thrown balls do not travel in arcs.
False. They do!
Why does a dropped ball fall downward?
A ball’s weight causes it to accelerate downward.
How many forces does a falling ball experience - name them.
Only one - it’s weight.
How differently do different balls fall?
No difference, they all fall together! Acceleration is constant and downward and velocity increases in the downward direction.
True or False: a ball’s weight is proportional to its height.
False. A ball’s weight is proportional to its mass.
Define mass.
The amount of “stuff” contained by the obejct.
What is the ratio of the acceleration due to gravity?
9.8 Newtons / Kilograms
OR
9.8 Meters / Second^2
(both are equal to each other)
How would a ball fall on the moon and why?
It would fall more slowly because the moon’s gravity is weaker than earth’s, so the acceleration due to gravity is less.
Why is the moon’s gravity weaker than earths?
Because gravity depends upon the mass of the planet and the distance from the center and the moon’s mass is small. Its acceleration due to gravity is about 1/6th of earth’s.
True or False: earth’s gravity varies slightly with location.
True. You weigh slightly less at the equator than at the North or South pole, or on a mountaintop than in a valley.
How does a falling ball move after it is dropped?
It accelerates downward, covering more distance each second
How can a ball move upward and still be falling?
Its initial velocity may be upward but it is still accelerating downward because its acceleration is purely vertical.
How does a ball’s horizontal motion affect its fall?
It doesn’t, the ball falls vertically but COASTS horizontally.
