Monday, 05 August 2013 13:01

## C2-21 PROJECTILES DROPPED AND SHOT

• ID Code: C2-21
• Purpose: Demonstrate the independence of horizontal and vertical components of motion
• Description:
A latchable spring launching mechanism is mounted at the top of a stand. Two metal cubes are attached to the mechanism. When the latch is released, one cube will be projected horizontally while the other is dropped straight down. They strike the floor at the same time.
##### Engagement Suggestion
• Before showing the experiment, challenge students to predict what will happen. Will the horizontal motion of one pellet make it strike the floor before or after the other?
• Afterwards, discuss why or why not.
##### Background

The gravitational force on each of the cubes is the same, so they experience the same downward acceleration. So since they started from the same height with zero vertical velocity, they reach the floor at the same time, even though one has traveled some distance horizontally in the meantime.

This is an example of the independence or separability of the components of motion. We can define the axes along which we measure, and treat vectors as the sum of their components along those axes.

• Availability: Available
• Loc codes: FS2