Acceleration Changing Velocity Acceleration Acceleration The rate at

Acceleration Changing Velocity

Acceleration • Acceleration - The rate at which velocity changes over time. • An object accelerates if its speed, direction or both changes.

What is accelerating? • When an object has an increase in velocity is commonly called positive acceleration. • When an object has a decrease in velocity is commonly called negative acceleration, or deceleration

Calculating final velocity starting velocity average acceleration = time it takes to change velocity

Graphing Acceleration

Going in Circles • Centripetal Acceleration • An object traveling in a circular motion is always changing its direction. Therefore velocity is constantly changing.

Practice Problems • A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its average acceleration? • A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds. What is his acceleration ? • A car accelerates from 0 to 30 m/s in 8 seconds, what is it’s acceleration? • A car advertisement states that a certain car can accelerate from rest to 1176 m/s in 7 seconds. Find the car’s average acceleration.

Answers 2 • 6 m/s 2 • 2. 7 m/s 2 • 3. 75 m/s 2 • 168 m/s

Think Pair Share In a pair answer the following questions • Is a fan accelerating? • Can you have constant speed but still be accelerating? • Give an example

Critical Thinking • If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 50 m/s/s for 3 seconds, what will its final velocity be? • 160 m/s • Falling objects drop with an average acceleration of 9. 8 m/s 2. If an object falls from a tall building, how long will it take before it reaches a speed of 49 m/s? • 5 s