Presentation on theme: "Take out your homework. Take 5 minutes to prepare for your quiz Objective: To differentiate between speed and acceleration. Key Terms: speedaverage speed."— Presentation transcript:
Take out your homework. Take 5 minutes to prepare for your quiz Objective: To differentiate between speed and acceleration. Key Terms: speedaverage speed instantaneous speed acceleration
SPEED Speed is the ratio of the distance an object moves to the amount of time the object moves. Average speed is computed for the entire trip while instantaneous speed is measured at a particular instant.
Average Speed Average speed is calculated by dividing the total distance travelled by the total time it took.
Instantaneous Speed The rate at which an object is moving at a given instant in time. The reading on a car speedometer is an example of instantaneous speed.
Graphing Motion The slope of a line on a distance versus time graph is speed.
Velocity Description of both speed and direction of motion Velocity is combined by vector addition
Recap What is the difference between instantaneous and average speed? How do we calculate speed?
DO NOW Take out your homework What is the difference between average speed and instantaneous speed? Objective: To be able to calculate speed and acceleration.
Acceleration Can be described as a change in speed, changes in direction, or changes in both. Acceleration is a vector. An example of acceleration due to a change in speed is freefall. An example of acceleration due to a change in direction is riding a bicycle around a curve. Constant acceleration is a steady change in velocity.
Calculating Acceleration Acceleration = change in velocity/time Unit is m/s 2
Graphing Acceleration The slope of a speed versus time graph is acceleration. A positive slope shows an increase in acceleration, a negative slope shows a decrease in acceleration, and a flat line shows constant speed.