Projectile Motion Reflection on Learning

Our class discussed and experimented with the concept of projectile motion. We articulated our understanding of the conceptual aspect of projectile motion by writing on a whiteboard.

Using the Video Physics App on our iPads we recorded and analyzed the path of a basketball shot into the air. The app created graphs based off of the ball's trajectory.

The graphs demonstrate that the basketball moves in two dimensions, horizontal (Vx) and vertical (Vy),  and that gravity is the only force acting upon the object. The basketball shares similar traits to that of a projective which is defined as an object that moves in 2D with only the force of gravity acting.

The graphs also indicate that the basketball, and projectiles in general, move at constant velocity as indicated by the constant slope of they graph in the upper right corner. When the averages of the slope were averaged out among the class, the result was a slope of 10.2. This number is consistent with the gravitational force of the earth which is generally 10 N/kg.

In this experiment, human error was a major factor because the measuring of the ball's trajectory was done manually.

Forces in 2D and Circular Motion

Big Questions: 

What is a projectile? What is the general path of motion? Why?

Why do things fall? What is the acceleration due to gravity? Do heavier objects fall faster than lighter objects?

A projectile is an object moving in two dimensions in which the only force acting on it is gravity. The path of motion moves back towards the Earth because of the influence of gravity. All objects will fall at the same rate if the air does not act to slow them down (less air resistance).

1. What does it mean to analyze forces in 2D?
2. How do forces cause objects to move in a circle?
3. What does it mean to be in orbit? How do satelittles orbit planets? How do planets orbit the sun?

-Analyzing forces in 2D means to understand the behavior of forces in 2 dimensions, using both x and y coordinates. 

-Centripetal force causes objects to move in a circle. It is a "center-pointing" force in which a net force act towards the center of the circle. Force and velocity are perpendicular and tangent. Ex: The moon's continual orbit of the Earth.

- In regards to orbit, when an object is moving in a circle, it is accelerating. Its speed is not changing, yet, its direction of motion is changing. It also needs to experience an unbalanced force.