1. Speed and velocity

2. The speed is the distance traveled divided by the time taken. The velocity is the change in position divided by the change in time. Equations

3. Are speed and velocity just two different words for the same thing? Speed versus velocity In everyday life you probably use the words speed and velocity interchangeably. In physics class, speed and velocity are related, but not exactly the same.

4. Click the interactive calculator on page 80 on speed. Exploring the ideas

5. See if you can come up with an example of when an actual object might move at each speed. a)0.1 m/sabout 0.22 mph (10 cm/s), the tip of the second hand on your clock b)1 m/s 2.2 mph, a slow walk c)10 m/s22 mph, a brisk bike riding speed d)100 m/s220 mph, a supercar’s top driving speed e)1000 m/s 2,200 mph, about the F14 fighter jet’s top speed How fast is fast?

6. Distance is always positive. Time is always positive. Therefore, speed is always positive! speed Speed So how do we tell the difference between moving backward and forward?

7. The velocity is defined as the change in position divided by the change in time. Velocity Moving forward is a positive velocity. Moving backward is a negative velocity. A change in position, Δx, can be positive or negative. That means that velocity can be positive or negative. velocity

8. Click the interactive calculator on page 80 on velocity. Exploring the ideas

9. Velocity can have negative or positive values. The sign of the velocity tells you the direction of motion. Velocity is a vector. A vector is a type of variable which includes directional information in a mathematically useful way. Velocity is a vector

10. 1.A swallow moves 80 meters in 5 seconds. What is its speed? What is its velocity? How can the two be different? Assessment

11. 1.A swallow moves 80 meters in 5 seconds. What is its speed? What is its velocity? How can the two be different? 2.Write an English sentence that means the same as this equation: Assessment The speed is 16 m/s. The velocity could be either +16 m/s or -16 m/s depending on the bird’s direction.

12. 1.A swallow moves 80 meters in 5 seconds. What is its speed? What is its velocity? How can the two be different? 2.Write an English sentence that means the same as this equation: Assessment The speed is 16 m/s. The velocity could be either +16 m/s or -16 m/s depending on the bird’s direction. The velocity is the change in position divided by the change in time.