Rockets & Model Rocketry

MMy rocket journey

Tick each stop when you finish it. Motors and launches are always run by an adult.

W1Balloon rocket data

Lesson 1 · Newton's three laws

Words: force · mass · inertia · acceleration · action and reaction · thrust

Question: Does more air make it go further? Does more weight make it go less far?

My guess:

Part A: more air (same mass)

Part B: more mass (same air)

Mean = (trial 1 + trial 2 + trial 3) ÷ 3. Only the mass changes in Part B: that makes it a fair test.

Think about it

1. Newton's third law: the balloon pushes air out the back. What pushes the balloon forward?
2. Newton's second law: in Part B, the push was the same. What happened when you added paper clips? Why?
3. Newton's first law: why did the straw stay still until you let go? Why did it stop at the end?
4. Rocket Builder: press ▶ Watch it launch. Write three things you noticed.

W2Forces and launch angles

Lesson 2 · The forces in a rocket flight

Words: thrust · weight · drag · lift · balanced · unbalanced · apogee

Part 1: draw the forces

Draw an arrow for each force on the rocket and label it: thrust, weight, drag. Make bigger forces longer arrows.

Which pictures show balanced forces?   Which show unbalanced?

Part 2: launch-angle test (straw rockets)

1. Which angle went furthest? Why do you think so?
2. Rocket Builder: press ▶ Watch it launch. Number these in the order you see them: ___ coast  ___ liftoff  ___ parachute  ___ top (apogee)  ___ boost
3. The power bar (thrust ÷ weight) for my rocket says ______ ×. Is it 5× or more? ______

W3Swing test

Lesson 3 · Stability: balance point and push point

Words: stable · unstable · balance point (CG) · push point (CP) · caliber · stability score

The blue dot (balance point) must be in front of the red dot (push point). Score (cal) = (push point distance − balance point distance) ÷ body width. 1–2 cal is just right.

Body width of my test rocket: cm  (= 1 cal)

1. Which version was the most stable? Use your scores to explain.
2. Why did clay in the nose help, but clay at the tail hurt?
3. A rocket is 3 cm wide. Its push point is 4.5 cm behind its balance point. Score = ______ cal. Is that just right, wobbly, or too stable?
4. In Rocket Builder, my rocket's score is ______ cal. The fins are shaped.

W4Drag test

Lesson 4 · Drag and shape

Words: drag · streamlined · frontal area · drag coefficient · variable · fair test · trade-off

The variable I'm changing: nose shape. Things I keep the same:

Test 1: nose shapes (launch angle: ______°)

Test 2: fins

1. Which nose had the least drag? How do you know?
2. Was the difference big, or could it be luck? What would make you more sure?
3. Explain the fin trade-off using your data.

W5Motor codes and impulse

Lesson 5 · Motors, impulse and energy

Words: propellant · nozzle · delay · ejection charge · igniter · total impulse · impulse class · thrust-to-weight

Motor rockets are 12+, and only adults handle motors and igniters. This drawing shows the inside of a motor. Never open one.

1. Decode the motor codes

2. Impulse = average thrust × burn time

3. Rocket Builder: How high will it go?

The best motor for my design is ______. It should reach ______ m, at a top speed of about ______ m/s.

4. Thrust-to-weight (it must be 5 or more)

100 g weighs about 1 N. So a rocket of 80 g weighs about 0.8 N.

1. Rocket + motor = 80 g. Motor average thrust = 5 N. Weight = ______ N. Thrust ÷ weight = ______. Pass? ______
2. Rocket + motor = 120 g. Motor average thrust = 4.7 N. Weight = ______ N. Thrust ÷ weight = ______. Pass? ______

5. Where is the energy?

Write the energy at each point: stored (propellant), kinetic (motion), potential (height), heat (drag). On the pad: Boost: Apogee:

W5bThrust curveExtension

Lesson 5 · Extension: impulse is the area under the thrust curve

This table is a thrust curve for a B motor, rounded from a measured one. Thrust is how hard the motor pushes at each moment.

1. Plot the points on the grid and join them with straight lines. Time along the bottom (each small square = 0.02 s), thrust up the side (each small square = 0.5 N).

2. What is the peak (highest) thrust? ______ N. When? ______ s
3. The area under the curve is the total impulse. Find it by splitting the shape into triangles and rectangles (or count squares: each small square = 0.02 × 0.5 = 0.01 N·s). Total impulse ≈ ______ N·s. Class: ______
4. Average thrust = total impulse ÷ burn time (0.86 s) = ______ N. Why is the code's middle number a little different?
5. F = m × a at liftoff. Rocket + C6 motor: mass 0.086 kg, measured average thrust 4.7 N. Weight = 0.086 × 9.8 = ______ N. Net force = ______ N. Acceleration = ______ m/s².

W6Design log

Lesson 6 · Design with a computer model

The trend: as the height went up, the score

Decision table: score each design 1 (poor) to 3 (great)

I chose design # ______ because

Advanced (custom fins): span 15 mm ______ cal · 20 mm ______ · 25 mm ______ · 30 mm ______. The score crosses 1.0 at about ______ mm.

▶ Watch it launch: it went up about ______ m and landed about ______ m from the pad.

W7Parachutes and landing energy

Lesson 7 · Parachutes and landing energy

Landing energy: KE = ½ × mass × speed²

Your rocket's parachute (Rocket Builder)

Parachute size: ______ inches. Descent speed: ______ m/s. Predicted altitude: ______ m.

Time to come down = altitude ÷ descent speed = ______ s.   Drift in a 10 mph (4.5 m/s) breeze = time × 4.5 = ______ m.

1. Practice: a rocket reaches 120 m and falls at 4 m/s. Time = ______ s. Drift = ______ m. Is a 60 m field big enough? ______
2. Why not just use the biggest parachute you can find?

W8Altitude tracking

Lesson 8 · Measuring height with angles

height = baseline × multiplier + eye height

1. How tall is it? (tree, flagpole or house)

2. Practice

1. Baseline 25 m, angle 40°, eye height 1.3 m. Height = ______ m.
2. Baseline 80 m, angle 55°, eye height 1.5 m. Height = ______ m.
3. Scale drawing: on the back, draw a baseline of 10 squares (1 square = 2 m). Draw a 35° angle at one end and a line straight up at the other. How many squares tall? ______ = ______ m.

3. Track a stomp rocket

4. Name two things that could make a height measurement wrong.
5. Extension (tangent): with a 50 m baseline, an angle of 45° gives ______ m and 47° gives ______ m. At 75°: ______ m; at 77°: ______ m. Which angle is more sensitive to a 2° mistake?

W8bSafety rules

Lesson 8 · The NAR Model Rocket Safety Code and classroom rules

Words: safety code · launch controller · safety key · misfire · LCO · RSO · preflight check

1. Is it safe?

2. Launch team jobs

W8cLaunch checklists

Lesson 8 · Get ready for launch day

1. Weather check

Forecast wind: ______ mph. Under 20 mph? ______ (Under 10 mph means less drift.)   Rain? ______   Burn ban or very dry grass? ______

2. Field check

Field size: ______ m by ______ m.   Rocket Builder's suggested field: ______ m. Big enough? ______   If not: a smaller motor that still gets a ✓, or a club launch.

3. Preflight checklist (printed rocket, with an adult)

4. Launch box

• Safety glasses for everyone
• Inclinometers, tape measure, stopwatches, flight log on a clipboard
• Rocket, spare wadding, warm-up stomp rockets
• Adult only: motors, igniters, the safety key
• Pad, rod, blast deflector, controller, fresh batteries
• Bucket of water or extinguisher; water, hats, sunscreen

W9Graph your data

Lesson 9 · Data and graphing

My data set: (from Lesson ______, or prediction vs flight)

Graph type: bar graph / line graph / scatter plot (circle one).   Remember: a title, labels on both axes, units, and evenly spaced numbers.

Mean of one group of trials: ( ______ + ______ + ______ ) ÷ 3 = ______    Range = ______ − ______ = ______

1. As went up, went .
2. One thing that might have made my data less accurate is
3. Draw a line of best fit by eye. Is the relationship a straight line? Where does it bend?

FFlight log (printed rocket)12+ only

Lesson 9 · Launch day: predict, fly, compare

Altitude = baseline × multiplier (or × tan of the angle) + eye height. Average the trackers. Percent difference = (predicted − measured) ÷ predicted × 100.

CMission report planner and rubric

Lesson 9 · Mission report

Make a poster, slides, a written report or a 3–5 minute talk. Plan each part here.

Rubric

Total ______ / 20. 17–20 mission accomplished · 13–16 solid flight · 9–12 needs another iteration · below 9 back to the pad.

QQuick checks, Lessons 1–5

Answer on the line. Answers are in each lesson plan and in the answer keys.

QQuick checks, Lessons 6–9

Answer on the line. Answers are in each lesson plan and in the answer keys.