AllExperts > Physics 
Search      
Physics
Volunteer
Answers to thousands of questions
 Home · More Physics Questions · Answer Library  · Encyclopedia ·
More Physics Answers
Question Library

Ask a question about Physics
Volunteer
Experts of the Month
Expert Login

Awards

About Us
Tell friends
Link to Us
Disclaimer

 
 
 
 
About James J. Kovalcin
Expertise
I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.

 
   

You are here:  Experts > Science > Physics > Physics > Speed, time and and distance

Physics - Speed, time and and distance


Expert: James J. Kovalcin - 11/7/2009

Question
can you please give me all the formulas for the 9th grade? and it should be about speed, time and distance. can you please explain when do when do we use them when solving a problem.


Answer
First of all there is no such thing as "all the formulas for the 9th grade"!
However, if you a asking specifically about the relationships among distance, velocity, acceleration and time, there are two:
Df=1/2*a*t^2+Vo*t+Do  and Vf=a*t+Vo
Where: Do is the position of the object aat the beginning of the problem
Df is the position of the object at the end of the problem
Vo is the velocity of the object at the beginning of the problem
Vf is the velocity of the object at the end of the problem
a is the rate at which the velocity is changing [the acceleration]
t is the time between the beginning and end of the problem
Since there are 6 distinct variables and two equations, any time that you can identify 4 of the 6 variables you can always solve for the other 2!

Add to this Answer   Ask a Question


 
User Agreement | Privacy Policy | Kids' Privacy Policy | Help
Copyright  © 2008 About, Inc. AllExperts, AllExperts.com, and About.com are registered trademarks of About, Inc. All rights reserved.