Free Fall and Projectile Motion

Active learning helps students confront misconceptions directly while building intuition for how forces and motion interact. When students measure, predict, and analyze real motion, they move beyond abstract formulas to see physics in action. This hands-on approach clarifies why free fall and projectile motion follow predictable patterns regardless of mass or angle.

• Grade 10
• Science
• 4 activities
• 25 min–45 min

Learning Objectives

1. Calculate the time of flight, final velocity, and distance for an object in free fall using kinematic equations.
2. Analyze the independent horizontal and vertical components of motion for a projectile launched at an angle.
3. Predict the trajectory, range, and maximum height of a projectile given its initial velocity and launch angle.
4. Compare the motion of objects in free fall with and without initial horizontal velocity, identifying key differences in their trajectories.
5. Explain the role of gravity as the sole force acting on an object during free fall and projectile motion.

Problem-Based Learning

⏱ 35 min·Pairs

Pairs Lab: Free Fall Measurements

Partners drop coffee filters, balls, and keys from set heights using meter sticks. Time falls with smartphones or stopwatches, recording five trials per object. Calculate average acceleration g and graph distance versus time squared.

Prepare & details

Explain how gravity uniformly accelerates objects in free fall.

Facilitation Tip: During the Pairs Lab, circulate to ensure students align the timing gate precisely with the ball’s release point to avoid timing errors.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 45 min·Small Groups

Small Groups: Ramp Projectile Launcher

Groups release marbles from adjustable ramps onto flat tables, measuring horizontal range and vertical drop. Vary launch heights and angles, tabulate data, and plot range versus angle. Predict maximum range location.

Prepare & details

Analyze the independent components of horizontal and vertical motion in projectiles.

Facilitation Tip: For the Ramp Projectile Launcher, remind groups to measure both launch height and horizontal distance from the same reference point to maintain consistency.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 30 min·Whole Class

Whole Class: Video Motion Analysis

Project a slow-motion video of a thrown ball. Class pauses to mark positions frame-by-frame on whiteboard. Separate horizontal and vertical motions on graphs, verifying constant horizontal velocity.

Prepare & details

Predict the trajectory and landing point of a projectile given initial conditions.

Facilitation Tip: When using Video Motion Analysis, set the frame rate to 30 fps or higher to capture smooth motion for accurate position-time graphs.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 25 min·Individual

Individual: Trajectory Prediction Sheets

Students receive scenarios with initial speeds and angles. Sketch trajectories, calculate landing points using components. Share and verify with class launcher demo.

Prepare & details

Explain how gravity uniformly accelerates objects in free fall.

Facilitation Tip: Before the Trajectory Prediction Sheets, review the independence of motion components with a quick whole-class example of a dropped vs. thrown ball.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Teaching This Topic

Teach this topic by first establishing free fall as the foundation, then layering on projectile motion as two independent motions. Avoid starting with complex equations; instead, let students derive the relationships through measurement and observation. Emphasize the role of air resistance only after they grasp ideal conditions, as it often obscures the underlying principles.

What to Expect

Successful learning looks like students confidently using kinematic equations to predict outcomes, explaining why horizontal and vertical motions are independent, and recognizing symmetry in projectile paths. They should articulate the role of gravity in free fall and describe how launch angle affects range without mixing up the components.

Watch Out for These Misconceptions

Common Misconception

During Pairs Lab: Free Fall Measurements, watch for students assuming heavier objects hit the ground first when comparing feather and ball drops.

What to Teach Instead

Guide students to crumple the feather into a tight ball and drop both objects simultaneously from the same height. Have them record times and graph the results side-by-side to observe identical fall times, reinforcing that mass does not affect acceleration in free fall.

Common Misconception

During Small Groups: Ramp Projectile Launcher, watch for students expecting the ball’s horizontal speed to decrease as it moves forward.

What to Teach Instead

Ask groups to mark equal time intervals along the table with tape, then measure the horizontal distance traveled in each interval. They should note the constant spacing, which demonstrates steady horizontal velocity. Ask them to explain what force would be needed to change that speed.

Common Misconception

During Small Groups: Ramp Projectile Launcher, watch for students believing 30-degree and 60-degree launches produce different rise and fall times.

What to Teach Instead

Have groups launch balls at both angles and use stopwatches to record the time from launch to peak and peak to landing. Direct them to compare the two times and discuss how the vertical motion’s symmetry creates equal durations regardless of angle.

Assessment Ideas

Quick Check

After Pairs Lab: Free Fall Measurements, present students with a scenario: 'A ball is dropped from a height of 15 meters. Ignoring air resistance, what is its velocity just before it hits the ground?' Ask students to show their calculations using the appropriate kinematic equation and hold up their answers on individual whiteboards for immediate feedback.

Exit Ticket

After Whole Class: Video Motion Analysis, give each student a card with a projectile’s parabolic path diagram. Ask them to draw and label vectors for horizontal velocity, vertical velocity, and acceleration at three points (launch, peak, landing) and write one sentence explaining why horizontal velocity remains constant.

Discussion Prompt

During Small Groups: Ramp Projectile Launcher, pose the question: 'Imagine two identical balls are launched horizontally from the same height at the same time. One is launched with a high horizontal speed, and the other with a low horizontal speed. Which ball hits the ground first?' Have groups discuss and justify their reasoning using the independence of motion components, then share conclusions with the class.

Extensions & Scaffolding

• Challenge early finishers to design a ramp launch that lands a ball in a target 2 meters away, adjusting only the launch angle and height.
• For students who struggle, provide pre-labeled graphs with missing values to complete during the Trajectory Prediction Sheets activity.
• Deeper exploration: Have students research how real-world projectiles like basketballs or water fountains account for air resistance in their paths.

Key Vocabulary

Free Fall	The motion of an object where gravity is the only force acting upon it. In free fall, objects accelerate downwards at a constant rate (approximately 9.8 m/s² on Earth).
Projectile Motion	The motion of an object launched into the air that follows a curved path (a parabola) under the influence of gravity alone. Its motion can be analyzed as independent horizontal and vertical components.
Acceleration due to Gravity (g)	The constant rate at which objects accelerate towards the center of the Earth due to gravitational pull. Its value is approximately 9.8 m/s² near the Earth's surface.
Trajectory	The path followed by a projectile moving under the action of gravity. For projectiles, this path is typically parabolic.
Horizontal Velocity	The component of a projectile's velocity that is parallel to the ground. In the absence of air resistance, this velocity remains constant throughout the projectile's flight.
Vertical Velocity	The component of a projectile's velocity that is perpendicular to the ground. This velocity changes due to the acceleration of gravity.