Kinematics

Motion Equations

Problem Solving With Constant Acceleration

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Do Now warm-up prompt

Motion Equations for problem solving with constant acceleration

Fill In The Blanks Notes

Warm-Up

One of these things is not like the other!

Motion diagrams to compare acceleration
Is the Acceleration Constant, Increasing or Zero?

Review

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Skateboard motion diagrams A, B, C
The idea for this game and graphic come from a great high school physics teacher named Kelly O'Shea.

Video Instruction

showmethephysics.com

IV. Motion Equations for Problem Solving

When an object is moving at a constant acceleration we can use the following equations to find motion information.

Bean riding a motorcycle

A. Constant Accel. Equations

(see Reference Table)

1. Average Velocity

V = (Vi + Vf)/2   or   V = Δd/Δt

2. Acceleration

a = (Vf − Vi)/t

Cross multiply & Solve: at = (Vf − Vi)

Add Vi to both sides

Vf = Vi + at

Rear engine dragster speeding

3. Displacement

V = Δd/Δt

B. Additional Equations

Take Equation 3 and solve for d

Δd = VΔt

Substitute Equation 1 into the previous equation

Δd = [(Vi + Vf)/2]Δt

Since Vf = Vi + at

Δd = [(Vi + (Vi + at))/2]Δt

Gather like terms and solve for d

Δd = Vit + ½at²

Bean riding a motorcycle

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