3.2 Motion With Constant Acceleration

3.2 Motion with Constant Acceleration If you know average acceleration (ā) during a time interval, you can find Δv. ā = Δv/Δt  Δv = ā·Δt  vf – vi=āΔt vf=vi + āΔt NOTE: if acceleration is constant; ā = a

3.2 Motion with Constant Acceleration vf=vi + āΔt (is the equation we just found) Can you rearrange the above equation to find time? Δt = (vf – vi)/a

Practice Problems 18a

Practice Problem 18b

Practice Problem 18c

Practice Problem 19

Practice Problem 20

Practice Problem 21

Position with Constant Acceleration Look at table 3-2; it is a position vs. time graph; the curved line shows it is accelerating. We can use the slopes from position/time graph to create a velocity vs. time graph

Position with Constant Acceleration However…a position vs. time graph cannot be created from velocity vs. time graph because there is no information about position, but it DOES tell information about displacement RECALL… v = Δd/Δt …therefore… Δd = vΔt

Picture of Velocity vs. time graph Area under a line = Δd = vΔt Therefore…area = the object’s displacement

Example Problem #3

Problem 22a

Problem 23

More Displacement…