You will interpret motion graphs to analyze the motion of an acrobat launched vertically.
After completing this tutorial, you will be able to complete the following:
Projectiles launched vertically move under a constant acceleration due to the force of gravitational attraction between the object and the Earth.
As a projectile moves upward, its speed decreases by 9.8 m/s every second. (It is generally acceptable to round this change in velocity to 10 m/s every second.) As the projectile's speed decreases, its displacement each second decreases until it reaches a maximum height, and its velocity is 0 m/s for an instant in time. However, it is important to note that the projectile's acceleration is a constant -10 m/s^2 throughout the path because the velocity is still changing during each second. Once the projectile reaches its maximum height, it changes direction and its position decreases. The projectile's displacement each second increases because it speeds up. The path traveled by the projectile is symmetrical due to the constant force of Earth's gravity acting on it.
The projectile's velocity and time spent in the air are directly proportional as it moves. If the projectile is launched vertically upward with a velocity of 50 m/s, it spends 10 seconds in the air before it returns to its initial height. However, if the initial velocity is doubled to 100 m/s, it will return to its initial position in 20 seconds.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Students should understand concepts of acceleration, displacement and velocity.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||acceleration, displacement, graph|