Velocity (Speed)

Average Speed (Vav) – the total distance divided by the total time for a trip Delta (∆) – “change in” ∆d – change in distance ∆d = df - di ∆t – change in time ∆t = tf - ti

Instantaneous Speed – the speed at which an object is traveling at a particular instant in time Constant Speed – Uniform Motion

Calculating Average Speed When solving problems, GUESS: G iven – Write down all knowns (with units) U nkown – Write what you’re trying to find E quation – Write down the formula to be used S olve (plug in) – Fill in your formula with knowns (including units) S olution (units & SF) – Write the answer with units AND proper sig figs

Need to Know: Manipulating Formulas! Solve for t. Show your work! Vav

Solve for d. Show your work! Vav

Need to Know: Units We will be working with the following units: - Velocity – always distance over time Write in different velocity units: Km/hr m/s Miles/hour

- Distance Write in different distance units: Km Miles m

- Time Write in different time units: Seconds (s) Minutes (min) Hours (hr)

What are your knowns? Use the units as a hint! 1. Joshua skates to school, a total distance of 4.5 km. He has to slow down twice to cross busy streets, but overall the journey takes him 0.62h. What is Joshuas’s average speed during the trip?