You will investigate the factors affecting how far projectiles travel.
After completing this tutorial, you will be able to complete the following:
An object that is projected horizontally has a constant horizontal velocity but an increasing vertical velocity. Gravity applies an unbalanced force on the object, changing its motion from forward only to forward and downward, causing it to appear to move along a curved path. An object projected horizontally and an object dropped from the same height will reach the ground at the same time. The same force of gravity is acting on both objects, and they have the same vertical acceleration (9.8 m/s2). Because of this, people who project objects at a target usually aim above the target or project the object at an upward angle in order to reach the target or project the object as far as possible. Projectile motion refers to the motion of an object propelled into the air at an angle. A soccer player kicking a ball, a track athlete doing a long jump, and a person throwing a dart at a target are examples of projectile motion.
In this Activity Object, learners combine principles of force and motion to determine how to shoot an arrow the farthest possible distance. They learn that pulling back the bow more gives the arrow greater initial speed. The initial speed and how far a projectile travels are directly related. Learners discover that the angle from which an arrow is fired affects how far it travels. Angles less than 45° and the distance the arrow travels are directly proportional, but angles greater than 45° and the distance the arrow travels are inversely proportional. They also learn that according to Newton's Second Law of Motion, the mass of an object affects its initial speed. The less mass the object has, the higher its initial speed. Therefore, in order to shoot the arrow the farthest possible distance, the arrow with the least mass should be chosen, the bow should be pulled back as far as it can, and the arrow should be shot at a 45° angle from the ground to the direction of motion.
|Approximate Time||25 Minutes|
|Pre-requisite Concepts||Students should be familiar with force and motion.|
|Type of Tutorial||Experiment|
|Key Vocabulary||angle, arrow, directly proportional|