Speed, Velocity, and Acceleration Lesson 2

Speed, Velocity & Acceleration

By Nnenna Crockett

How Things Move and Why It Matters

​Today, we’re exploring how objects move—how fast they go, how direction affects motion, and what acceleration really means.

Learning Objectives:

• Calculate and interpret speed using the formula speed = distance ÷ time

• Understand the differences between speed, velocity, and acceleration

• Analyze real-world scenarios involving motion

• Interpret motion graphs

If a car travels 100 km in 2 hours, its speed is 50 km/h.

​Example

Definition: Speed is how fast an object is moving.
Formula: Speed= Distance/Time

​Speed

What is Speed?

Total distance/total time

​Average

The speed at any given moment

​Instantaneous

Instantaneous and Avg Speed

Multiple Choice

Vivian rode 24 km in 1.2 hours. What was her speed?

• 0.05 h/km

• 20 mi/h

• 20 km/h

• 28.8 km•h

​Velocity

Definition: Velocity is speed in a given direction.

Example: 30 km/h north vs 30 km/h south → different velocities

Fill in the Blank

Pace explained his average speed was 38 km/h, but the fastest speed he went was 60 km/h.
His 38 km/h is his average speed, and 60 km/h is his ______________ speed.

​Acceleration

Definition: Acceleration is the rate at which velocity changes.

• Speeding up

• Slowing down

• Changing direction
  Visual: Roller coaster starting, stopping, and turning

Multiple Select

How can the antelope use velocity to escape a lion? (Select 3)

• Run at the same speed but change direction

• Run in same direction but increase speed

• Increase speed and change direction

• Decrease speed and keep going same direction

​Real-World Application

Example: A golf ball in motion

• Hits ball → changes direction

• Goes up → slows down

• Comes down → speeds up

• Eventually stops
  Concepts: Acceleration = changing speed or direction

Multiple Choice

Which does NOT describe the ball’s acceleration?

• It increases speed

• It decreases speed

• It changes direction

• It moves in the same direction

​Using Graphs to show motion

Line Graphs:

• Slope shows speed

• Rise/Run

• Steeper line = faster motion
  Carlos’ Bowling Example: Ball travels 18 m in 3 seconds
  Visual: Line graph (origin to point at 3 s, 18 m)

Multiple Choice

How far did the ball travel in 2 seconds?

• 6 m

• 9 m

• 12 m

• 18 m

​Calculating Average Speed from Graph

Calculating Average Speed from Graph

Carlos’ Graph:

Average Speed=18/3 s=6 m/s

Explanation: Find total distance, divide by total time

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Open Ended

What is the average speed of Carlos’ bowling ball? Explain how you found it.
✅ Answer: The ball moved 18 m in 3 seconds. Speed = distance ÷ time = 18 ÷ 3 = 6 m/s.

​Let's Review

Speed = Distance ÷ Time
Velocity = Speed + Direction
Acceleration = Change in velocity (speed or direction)

Multiple Choice

A train travels 120 km in 2 hours. What is its average speed?

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• 60 m/s

• 60 km/h

• 240 km/h

• 122 km/h

Multiple Choice

Velocity is the same as speed.

• True

• False

Multiple Choice

What does a flat horizontal line on a distance-time graph mean?

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• Acceleration

• Increasing Speed

• No motion

• Changing Direction

Multiple Choice

Which is an example of acceleration?

• Walking at a steady pace

• Turning a corner at the same speed

• Standing Still

• Using a stopwatch