A pullet fired verticaly aproached dstance of 12250m, how could I calculate the first velocity?

Question

I am in need for velocity laws (equations), please write it down for me.
Thanks in advance.

Answer 1

The equation to start with is D=0.5 x A x (T^2) - V x T
Use this equation to find T. You start with the bullet at V = 0 m/s, D = 12250 m and A = 9.81 m/s^2 (start at its highest point), how long does it take to hit the ground?

Once you know how long it takes to hit the ground you can calculate the velocity V, A x T.

This question totally ignores the notion of air resistance and terminal velocity. If these real world properties were included the set of variables would exceed what you are supposed to be learning.

Answer 2

JR's probably close enough for your solution, but 12.25km is high enough you might start seeing a change in the acceleration of gravity.

For a more general form, consider the change in potential energy to be |GMm/r² - GMm/R²| (which simplifies to mgh for r close to R). This will equal the magnitude of the change in kinetic energy, already shown in JR's solution.

Answer 3

v=root(2*g*H)
here H=12250 mts
v=root(2*9.81*12250)
=490.24 mts

Answer 4

v = sqr( 2 . g . e )
= sqr( 2 * 9.81 * 12250)
= sqr( 240345 )
= 490.25 m/s

Answer 5

v = m x a ( mass x acceleration)