Speed and Acceleration Objective SWBAT calculate speed and

Speed and Acceleration Objective: SWBAT calculate speed and acceleration WARM UP: 1. The Zombie Apocalypse has begun! Zombies run after you for 20 minutes at a speed of 05 miles/minute. How far have they chased you?

Calculating Speed Given Distance & Time 1. Leo ran 25 meters in 25 Divide Distance by Time seconds. What Distance ÷ Time was = Speed his speed? Speed = Distance ÷ Time

Calculating Distance Given Speed & Time 2. Erykah. Multiply walked at. Time a speed of Speed and. 5 m/s for. Distance 20 seconds. = Speed X Time. HOW FAR DID SHE Speed WALK? X Time = Distance

Calculating Time Given Distance and Speed 3. Emily raced a four Divide towards Distance by Time square ball. Distance 10 meters at a ÷ Speed =away Time speed of 2 Time m/s. HOW LONG DID IT = Distance ÷ Speed TAKE HER TO GET THERE?

There are types of speeds? • Calculating Average Speed handout Average speed= Total distance/Total time • Let’s do the worksheet together Constant Speed

Speed Trials Lab Problem: to calculate the speed of your toy car Review the notes at the top of the lab sheet WRITE in the box: Describe SPEED in your own words Share with your group!

Speed Trials Lab Materials: Stopwatch Toy Car (do not lose the car, please!) 1 meter board Calculator Several textbooks

• Who can read the procedures? • What would be some good expectations for this lab?

Graph your Data

Speed • Remind me… how do we calculate speed? • VELOCITY is similar to speed because we use the same formula, however, you have to add a DIRECTION

Velocity • Velocity: speed in a specific direction Example: your velocity could be that you are walking east at a speed of 2 meters/second A person walking NORTH with a speed of 2 meters/sec has the same speed as you do, but NOT the same velocity (they’re going in a different direction)

Determining Speed (Velocity) • Who can read the top paragraph? • Complete questions 1 -8 at your table

Reviewing Velocity Calculations • What did you get?

What do you think? • Did the SPEED and DIRECTION of the bouncy ball stay the same as the ball moved? • The bouncy ball’s velocity kept changing

Acceleration • You can find out how MUCH the bouncy ball’s position changed during a certain amount of time if we knew the velocity • We can also measure how the bouncy ball’s velocity changed over time • What does ACCELERATION mean in everyday life?

Moving on…. Demonstration Dropping a BOUNCY BALL • Does the bouncy ball leave your hand at a certain speed? • What happens to the speed of the bouncy ball as it rises? • What happens to the speed of the bouncy ball when it starts to fall back down?

Acceleration: The rate at which velocity changes with time (change in speed and/or direction) Velocity/Time (In physics, it’s ANY change in velocity) Example: car slowing down = accelerating because it’s changing its speed and/or direction Or. . A runner turning a corner accelerates because the direction of her velocity is changing as she turns

Does it Describe Acceleration? Let’s do the first one together… 1. Your pet dog runs around in circles, chasing his tail Is this describing ACCELERATION? Why or why not? Complete 2 -6 with your partners

Acceleration Formula acceleration = (final velocity - original velocity) time But when you find acceleration, it’s written like: Acceleration= 2 km/sec

Question! A roller coaster is constantly accelerating (changing its velocity) as it travels up and down and around To calculate the AVERAGE acceleration of a roller coaster, divide the change in velocity by the time it takes the velocity to change. acceleration = (final velocity - original velocity) time

Thrill Ride! Roller Coaster in Hong Kong A roller coaster's original velocity is 0 km/s and its final velocity is 20 km/s. The roller coaster ride takes 60 seconds to complete. Find the average acceleration = (final velocity - original velocity) time

At a Snail’s Pace: Applying the Main Ideas Before you begin. . 1. What is the formula for acceleration? 2. What is the final velocity, original velocity, and time described in the word problem? (circle them!) 3. THEN solve to find the acceleration of each snail! (questions 1 -3)