# 2.2 Acceleration Physics A.

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2.2 Acceleration Physics A

Objectives I can describe motion in terms of changing velocity.
I can compare graphical representations of accelerated and non-accelerated motions. I can apply kinematic equations to calculate distance, time or velocity under conditions of constant acceleration.

What are the units on acceleration?

Tip: Watch for implied data in the problems.
Practice Problem 1 With an average acceleration of -1.2 m/s2, how long will it take a cyclist to bring a bicycle with an initial speed of 6.5 m/s to a complete stop? Tip: Watch for implied data in the problems.

At the bottom of page 50 1, 2, and 3
Conceptual Challenge At the bottom of page 50 1, 2, and 3

Identify which values represent: speeding up, slowing down, constant velocity, speeding up from rest, or remaining at rest. Table Velocity and Acceleration vi a Motion + - - or +

Analyze the Following Graph

Velocity vs. Time Graph

For cases with constant acceleration
π£ ππ£π = π£ π β π£ π 2 & π£ ππ£π = βπ₯ βπ‘ Set these two equations equal to one another and solve for Ξx.

Displacement with Constant Acceleration
βπ₯= π£ π β π£ π βπ‘

Practice C 1. A car accelerates uniformly from rest to a speed of 6.6 m/s in 6.5 s. Find the distance the car travels during this time.

More useful equations:
We know: π= βπ£ βπ‘ = π£ π β π£ π βπ‘ Solve for π£ π in terms of a.

Velocity with Constant Acceleration
π£ π = π£ π +πβπ‘

One moreβ¦ We know: βπ₯= 1 2 π£ π + π£ π βπ‘ & π£ π = π£ π +πβπ‘ Solve for a new Ξx.

Displacement with Constant Acceleration
βπ₯= π£ π βπ‘+ 1 2 π βπ‘ 2

Practice D Do problems 1-4

Final Velocity after any Displacement
vf2 = vi2 + 2aΞx

Practice E Problems 2 & 4

Equations for Constantly Accelerating 1-D Motion
βπ₯= π£ π β π£ π π£ π = π£ π +πβπ‘ βπ₯= π£ π βπ‘+ 1 2 π βπ‘ 2 vf2 = vi2 + 2aΞx