# Projectile motion

Introduction

By watching a weekend football game you could learn something other than who threw the most passes or gained the most yards.

Football provides some great examples of the basic concepts of physics!  Physics is present in the flight of the ball, the motion of the players and the force of the tackles.

In this investigation you will learn the characteristics of projectile motion which is the kind of motion followed by the ball.

By the end of this PhysicsQuest you will have a better understanding of projectile motion by analyzing multimedia animations and completing a virtual lab activity.

Process

Part 1.

Parabolic Motion of Projectiles

The animation shows a comparison of a projectile thrown horizontally to an object in free-fall.

https://www.physicsclassroom.com/mmedia/vectors/bds.cfm

1. In the absence of air resistance, why does the horizontal component of velocity for a projectile remain constant, and why does only the vertical component change?

2. How does the downward component of the motion of a projectile compare to the motion of free fall?

3. At the instant a ball is thrown horizontally over a level range, a ball held at the side of the first is released and drops to the

ground.   If air resistance can be neglected, which ball - the one thrown or the one dropped from rest - strikes the ground first?

Part 2.

Both simulations show a situation where a plane and a truck are moving at constant speed. The plane drops a package from its luggage compartment and the truck projects a ball upward.

Neglecting the effects of air resistance, explain why after being thrown,  the package remains directly below the plane and the ball remains directly above the truck.

Part 3.

VIRTUAL LAB

Click on each link to complete the activity and complete the lab worksheet.

Evaluation

All the tasks will be evaluated with the following scoring rubric.

 Approaching (6 pt) Achieving (8 pt) Exceeding (10 pt) Content ~ amount Missing some of the content from exceeding section. Covers all material. Lacks including extra items to help present clearly. Contains explanation about free fall, vertical and horizontal, and angle launched projectiles. Uses examples for each. Content ~quality Missing some of the content from exceeding section. Brief explanations and examples. Simple. Excellent examples and definition of concepts. Clearly presents free fall, vertical and horizontal, and angled launched projectile motion correctly. Quality of presentation Unorganized. Sloppy. Organized but sloppy. Looks rushed. Neat and organized. Appropriate graphs and images. Knowledge of content Can not answer some of the basic questions. Needs prompts to help answer some of the questions. Answers all questions regarding presentation and material. (Approaching (2 pt) Achieving (3 pt) Exceeding (5 pt) Spelling Lots of errors found. Some errors found. No errors found.

Conclusion

Congratulations you have completed the WebQuest on Projectile Motion. Now that you have completed these 3 steps, that mean you have developed and shown proficiency in the area of projectile motion. You should be able to identify when an object is a projectile or not by its motion characteristics. You should be able to demonstrate the independence of horizontal and vertical velocity vectors. You should also be able to predict the trajectory path of a projectile. Finally you should have developed the ability to design and conduct and experiment and compare calculated results with measured results.

With these new skills go have some fun with this addicting game. Thanks Angry Birds!!