Teach lesson
Projectiles 2/3: velocity, time, and range
Use velocity, flight time, and result-image readings to compare predicted and observed range in the Projectiles lab.
Learning Outcomes
Record velocity, flight time, and image reading from three real launches.
Calculate predicted range with
R = v cos(theta) t.Compare the model with visible lab evidence without pretending the image is perfectly precise.
Student activity preview
Activity Content
Preview only. In a class session, students can fill in responses and submit their work to the teacher.
From launch to numerical prediction
8 min
Two launches can look similar and still land at different distances. To explain the difference, angle is not enough: it also matters how much forward velocity the projectile has and how long it stays in the air. In this activity, you will turn that idea into a numerical prediction and compare it with the real lab image.
To check this, you will use two values shown by the lab:
- velocity v;
- flight time t.
For a complete trajectory, predicted range is estimated using horizontal velocity as v cos(theta):
Predicted range
R_{predicted}=v\cos(\theta)t
You will use the same three angles, but now you will record velocity and time for a calculation.
Why does a launch with more flight time not always have the largest range? Use the words horizontal velocity and time.
Collect velocity, time, and image evidence
16 min
Run three launches: complete trajectory, low level, angles 35°, 45°, and 55°. In the lab UI, completa means complete trajectory, bajo means low, velocidad means velocity, and tiempo means time. Copy the velocity and time shown by the lab, then read approximate range from the result image.
To save time, use these cosine values: cos35≈0.82, cos45≈0.71, and cos55≈0.57.
The image reading is approximate. Use it as evidence, then mention one limitation in your conclusion.
Open the Projectiles lab
Choose complete trajectory (
completa) and low level (bajo).Launch at 35°, 45°, and 55°.
After each launch, wait for the final image.
Copy
velocidad(velocity) andtiempo(time) from the interface.Read the approximate distance on the image ruler.
Calculate predicted range for all three rows using the approximate cosines from this activity.
Velocity, time, and range
Complete one row per angle. For predicted range, multiply v by cos(theta) and t. Use cos35 about 0.82, cos45 about 0.71, and cos55 about 0.57. Keep units correct.
| Angle deg | Velocity m/s | Time s | Range read from image m | Predicted range m |
|---|---|---|---|---|
Calculate and compare
11 min
Choose one complete-trajectory row and calculate R_predicted = v cos(theta) t. Enter the result in meters and show the substitution with your values in the explanation.
Compare the angle with the largest predicted range and the angle with the largest range read from the image. Do they match? Cite at least two rows.
Conclusion with model and evidence
5 min
Write a short conclusion: what did the calculation add that was not as clear from only looking at the image? Include one limitation of the real measurement.