Name______J#______
Balloons and Newton's Third Law
KEY QUESTION/STATEMENT OF PROBLEM
How does Newton's third Law of Motion accelerate balloons of different sizes?
BACKGROUND
Newton's 1st Law of Motion is also called the Law of Inertia. Inertia is the ability of a substance to resist changes in motion. The amount of motion depends on the object's mass.
Newton's 2nd Law of Motion can be expressed as force equals mass times acceleration. It explains that force causes acceleration and mass resists acceleration. The more mass, the more force you need to make the object move. Acceleration is calculated by dividing change in velocity (final speed – initial speed) by time.
Newton's 3rd Law of Motion says that for every action force, there is a reaction force equal in strength and opposite in direction. The action/reaction forces act on separate objects, not the same object. Rockets use Newton's 3rd Law of Motion to help propel them. Traveling into space requires large amounts of energy! In this activity, you will use Newton's 3rd Law of Motion to propel balloons (different designs) across the classroom. Three balloons will be powered by escaping air, using Newton's 3rd Law of Motion. Their motion is determined by Newton's 1st and 2nd Laws of Motion. You will also use Newton's Laws to explain the movement of the balloon from launch until it stops.
HYPOTHESIS
Look at the key question above. Create a hypothesis.
MATERIALS
1 balloon tape stopwatch
1 straw clamp
string or fishing line meter stick
PROCEDURE
1. Run the string across the classroom to make a path for the balloon. Leave one end loose so you can place the straw through the string.
2. Thread the string through the straw.
3. Pull the string tightly and clamp down the loose end of the string.
4. Inflate your balloon. Inflate the first balloon ½ full of air. Don't tie the balloon!
5. Tape the straw on top of the balloon (standing at one end of the string, so it can travel the distance of the string).
6. Let go of the balloon. MAKE SURE you measure the travel time of the balloon. Have a back up timer!
7. Record the travel time (in seconds)
8. Measure the distance the balloon travelled and record.
9. Repeat steps 4-8 for trial 2 of this sized balloon.
10. Calculate your Average (Best Value) for Distance (and record).
11. Calculate your Average (Best Value) for Time (and record).
12. Calculate the average (final) speed of the balloon using your Average (Best Value) data for distance and time (and record). S = D/T.
13. Calculate overall acceleration for your balloon. (Final Speed-Initial Speed)/ Time.
14. Repeat steps 4-10, but now inflate balloon 2 ¾ full and balloon 3 COMPLETELY full of air.
SAFETY CONCERNS
Follow general safety procedures.
Limit the amount of walking around to reduce the risk of running into another group's set up. NO HORSEPLAY!
OBSERVATIONS/DATA
BalloonSizes / Distance
(Meters) / Initial Time
(Seconds) / Travel Time
(Seconds) / Initial Speed
(M/S) / Average as in NOT instantaneous Final Speed (M/S) / Acceleration
M/S2
Trial 1 / Trial 2 / Average (Best Value) DISTANCE / Trial 1 / Trial 2 / Average
(Best Value) TIME
Small / 0 / 0
Medium / 0 / 0
Large / 0 / 0
RESULTS
1. Draw a diagram showing all the forces acting on the balloons (think about our centers….the book on the table in Center 2).
CONCLUSION
1. What were the constants in today's lab?
2. Name two variables (one test and one outcome) in today's lab (ITMLX DORRY-Left/Right Data Table):
3. Was your hypothesis correct? Cite reasons why/ why not and include your data! This is a conclusion!
EVALUATION/ANALYSIS
1. Look at your data. Which rocket (balloon) went the greatest distance? Explain why.
2. Compare and contrast the speed of each balloon. Which balloon rocket has the greatest speed? Explain why.
3. Infer what aspects of the balloon made them travel faster or farther.
4. Use Newton's Laws of Motion to explain the motion of a balloon rocket from launch until it stops. Try your hardest to use ALL laws! (Use back of this paper if needed).