1. Speed, Velocity, and Forces Notes
Question: how do you know that an object is moving?
A frame of reference is a plane that includes all interactions and motion and allows you to tell if something is moving and how fast it is moving.
Practice: How do you know your hand is moving as you write? What is your frame of reference?

2. Speed, Velocity, and Forces Notes
Speed Definition: how fast an object is moving Units: Calculated with: distance/time Velocity Definition: the speed and direction of a moving object Units: meters/second Calculated with: distance/time AND describing the direction of the object. Acceleration/deceleration Definition: how fast an object is speeding up or slowing down Calculated with: speed/time Units: meters/second squared (m/s2)

3. Speed, Velocity, and Forces Notes
Example: The Bugatti, the fastest car in the world, can travel 240 meters in 2 seconds. The car takes off in the direction of the setting sun. What is the speed, velocity, and acceleration of the car? (Remember your units.)

4. Speed, Velocity, and Forces Notes
A cheetah can run approximately 4,650 m in 3 minutes while a gazelle can run 3,200 m in 2 minutes. Assume a cheetah is chasing a gazelle in the direction of the rising sun. What is the speed and velocity of the animals? Which one accelerates faster? (Hint: convert minutes into seconds before you calculate anything.)

5. Speed, Velocity, and Forces Notes
A force is a push or pull upon an object as a result from its interaction with another object. It has both magnitude and direction.
When the interaction stops, the two objects no longer experience the force. Forces only exist as a result of an interaction.
The two objects in the force interaction are called an action-reaction pair.
All objects on Earth have forces working on them, even objects at rest.
The more mass an object has, the more force it takes to move it.