What does x = 1/2gt² + v₀t + x₀ represent and what is g?

[hamudi786]

help me out here please

what exactly is this equation :

x=1/2gt(squared)+v0t+x0


and what is g

 

[Snazzy]

It's a kinematics equation relating the final and initial displacements, the initial velocity, time, and the acceleration of gravity, g.

 

[tiny-tim]

Welcome to PF!

Hi hamudi! Welcome to PF!

It's $$x(t)\,=\,\frac{1}{2}gt^2\,+\,v_0t\,+\,x_0\,,$$

and it's the constant-acceleration equation for the distance x reached after time t with constant acceleration g if you started (at time 0) at position x0 and with speed v0.

"g" usually means "gravity", by the way - if it was anything else, you'd probably use the letter "a" (for "acceleration", of course).

 

[astrosona]

Yes, Tiny-tim is correct; a (acceleration) in your equation is g because it is probably looking to y-axis and of course acceleration in y-axis is downward g

when ever you get confused what is a parameter you can look to its dimension too, in here g has acceleration dimension. [L/(T^2)]

 

[hamudi786]

hey thanks ...that was a great help =)

 

[hamudi786]

wat exactly is the purpose of the equation

 

[Snazzy]

For physics problems relating those variables.

 

[hamudi786]

can the constant g change ... like for example in one testing of an object it is 9 and on the other object( a diffrent one) 10.6 ...is this possible

 

[sealedhuman77]

no g is always equal to -9.8 m/s^2. though the sign changes according to the orientation of the coordinate system

 

[mikelepore]

It depends only on location. We have this value of g near the surface of the earth. Slightly different values in cities of different altitudes -- in Poughkeepsie, New York it happens to be 9.80665 -- but who cares about the way-out decimal places? It changes slightly while falling through different altitudes, if it's a very long drop. Very different values on other planets -- on Mars it's about 3.2 m/s^2.

 

[tiny-tim]

can the constant g change ... like for example in one testing of an object it is 9 and on the other object( a diffrent one) 10.6 ...is this possible

Hi hamudi!

As mikelepore says, it changes in different locations.

But in the same place, it does stay the same.

(If it didn't, we wouldn't use the letter "g".)

 

[hamudi786]

thx...well yeah that does make sense