# Can Anyone Help Me Understand Kinematics?

1. May 15, 2010

### TECH GEEK

Can Anyone Help Me Understand Kinematics???

I just need to know a little more about 1-d kinematics.
Note: I have read the definition and the formulas but I still need help!!!!!!!

Thanks for any help!!!! It is all gladly appreciated!!!!

2. May 15, 2010

### nicksauce

Re: Can Anyone Help Me Understand Kinematics???

Well, what is it exactly you don't understand? We can try to help you, sure, but we need to know where to start.

3. May 16, 2010

### TECH GEEK

Re: Can Anyone Help Me Understand Kinematics???

Just how to use the foumulas and what each one does also thier names.

V = Vo + at
X - Xo = Vot + .5at2
v2 = vo2 + 2a(X - Xo)
X - Xo = .5(Vo + V)t

Thanks again
Also if I am missing any fourmulas let me know
(I just want the formulas that relate to 1d and 2d kinematics)

Last edited: May 16, 2010
4. May 16, 2010

### Redbelly98

Staff Emeritus
Re: Can Anyone Help Me Understand Kinematics???

Your list is complete for 1d kinematics problems with constant acceleration.

For starters, you have to understand there are 4 distinct types of quantities that appear in these problems:
• time
• displacement
• velocity, the rate of change of displacement
• acceleration, the rate of change of velocity, assumed constant
We usually assume t=0 initially. Also, the initial displacement is often zero as well, or if not it should be given or somehow obvious from the problem statement.

So apart from initial time and displacement, there are 5 quantities of interest in kinematics problems with constant acceleration:
• final time, t
• final displacement, x
• initial and final velocities, v0 and v
• acceleration, a
You can approach any 1-d kinematics problem as follows:
• Is the initial displacement x0 = 0, or something else?
• Make a checklist of the 5 quantities t, x, v0, v, and a
• Which of those 5 quantities are given in the problem statement?
• Which of those 5 quantities are you asked to find?
• Figure out which equation from your list contains the given quantities and asked-for quantity, and solve it.
Note: you must be given, or be able to figure out by other means, three of the 5 quantities. A 1-d kinematics problem can't be solved until you know the values of 3 of them.

Hope that helps, if there are more questions feel free to ask.

Last edited: May 16, 2010