2. Acceleration: the rate of change of velocity with respect to time a avg = Δv/Δt = (v f –v i )/(t f -t i ) Notice how this form looks similar to that of velocity (Δx/Δt) Just as the slope of x vs t is velocity, the slope of v vs t is acceleration

3. Quick math questions A car can accelerate at a rate of 2m/s 2. How long will it take for the car to reach a speed of 30 m/s? What is the rate of acceleration for a car that slows from 30 m/s to a stop in three seconds?

4. Variables of linear motion d = displacement ( Δ x) t = time of travel ( Δ t) a = rate of constant acceleration v i = initial velocity v f = final velocity

6. Key Steps in Problem Solving

7. Practice # 1 A car travelling at 10.0 m/s accelerates at a rate of 2.5 m/s 2 to a final velocity of 20. m/s. How long does it take for this to occur?

8. Practice # 2 A plane must reach a speed of 100 m/s at take off. If it takes 10 seconds to get down the runway, how long does the runway have to be?

9. Practice #3 Upon lift off, a rocket ship accelerates at a rate of 1 m/s 2. How fast is it travelling when it reaches a height of 10,000 m?

10. Theory behind the lab  We know:d = v i t + ½ a t 2  If you drop something, v i = 0, so the equation reduces to:d = ½ at 2  If you rearrange with a on the left you get a = 2d/t 2  This lets you find the acceleration of an object due to gravity!!  You can also determine the slope of a graph of v vs. t to get a. We will do this too.