Agenda – 95 min 1.AS: KWLSpeed/Velocity 2.INM: Notes 3.GP: Geico Gecko 4.IP/HW

Speed and velocity

Bell Ringer: What do you already know about speed and velocity?

SpeedVelocity Speed is a scalar quantityVelocity is a vector quantity Speed is the change in distance over the change in time Velocity is the change in displacement over the change in time Speed will be constant if you move at the same rate. Velocity will be constant if you move at the same rate in the same direction Speed is always positive.Velocity can be positive or negative depending on which direction you are moving Speed and velocity can often be the same. But the two are NOT used interchangeably in physics As we move forward, think when they would be the same and when they would be different

Calculating speed Speed depends on two things ▫Distance (how far an object traveled) ▫Time (how long it took to travel) If you want to calculate speed, how do you put distance and time together mathematically? ▫You just came up with a physics formula! Good job young scientist!

The formula for speed and velocity looks like: ▫v = velocity  measured in m/s or km/hr ▫∆d = change in displacement  measured in meters, kilometers, centimeters, etc. ▫∆t = change in time  measured in seconds, minutes, hours, etc. Remember?! A change in any quantity, indicated by the Greek symbol delta (∆) is equal to the final value minus the initial value. v=∆d ∆t

Remember: LESS is MORE List Equation Solve State All answers MUST be set out correctly! “This is how to ALWAYS set out your answers. Make it so.”

Let’s try this! We will be solving word problems from here on out, and I would like us to follow these five simple steps: 1.Draw a picture 2.List the given information 3.Identify the unknown variable 4.Write the appropriate formulas 5.Plug and solve

I DO A cheetah, the fastest animal in the world, ran at you for 6 seconds and covered 180 m. What’s its speed? (Do you think you can out run it?)

WE DO Lightening Bolt ran 100 m in 9.5 seconds. What is his speed to 1 decimal point? (do you think you can beat him?)

YOU DO Please practice solving the rest of your worksheet