Projectile Motion
Pronunciation: /prəˈdʒɛk.taɪl ˈmoʊ.ʃən/ Explain
Projectile motion
is the vertical motion of an object in a gravitational field given an initial
velocity
and
height.
The
quadratic equation
for projectile motion is:
where
t represents time,
a represents
acceleration
due to gravity,
v_{0} represents
the initial
velocity,
and
h_{0} represents initial
height.
Since down is taken to be negative, acceleration due to gravity is a negative
number.
Manipulative
Click on the blue points on the sliders and drag to change the figure.
What initial angle would make the projectile go only up or down?

Manipulative 1  Projectile Motion Created with GeoGebra. 
Example
 Jeff is standing on top of 20 foot tower. He throws
a stick down at an initial velocity of 10 ft/s. Use
32 ft/s^{2} for the acceleration due to gravity.
What is the equation for the vertical height of the stick? At what time does the stick
reach the ground?
Step  Equation(s)  Description 
1   Identify the values of the constants. 
2   Plug the constants into the equation. Simplify the equation. 
3   Set the height to zero. 
4   Apply the quadratic formula. 
5   Since a negative solution does not make sense in this problem, the negative solution is extraneous solution. Discard the extraneous solution. 
Example 1 
References
 McAdams, David E.. All Math Words Dictionary, projectile motion. 2nd Classroom edition 201501084799968. pg 145. Life is a Story Problem LLC. January 8, 2015. Buy the book
Cite this article as:
McAdams, David E. Projectile Motion. 4/28/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/p/projectilemotion.html.
Image Credits
Revision History
4/28/2019: Changed equations and expressions to new format. (
McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (
McAdams, David E.)
12/1/2018: Removed broken links, updated license, implemented new markup, updated geogebra app. (
McAdams, David E.)
8/7/2018: Changed vocabulary links to WORDLINK format. (
McAdams, David E.)
1/10/2009: Initial version. (
McAdams, David E.)