- #1
philipp2020
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I just have a question concerning a previous thread about gravitation.
The formula is from post 19 at https://www.physicsforums.com/showthread.php?t=635188&page=2
v= dr/dt
a = dv/dt
multiply by dv/dt by dr/dr:
a = (dr dv)/(dt dr) = v dv/dr
This gets you to the first step:
v dv/dr = -G (m1 + m2) / r2
My question is: Why is it possible to set a = v dv/dr = -G (m1 + m2) / r2 ?
On the left side there are units of acceleration (m/s^2) and on the right side is the gravitational force (kg*m/s^2). Shouldn't the units at all time be the same on both sides?
Thanks very much for an answer.
Regards, Philipp
The formula is from post 19 at https://www.physicsforums.com/showthread.php?t=635188&page=2
v= dr/dt
a = dv/dt
multiply by dv/dt by dr/dr:
a = (dr dv)/(dt dr) = v dv/dr
This gets you to the first step:
v dv/dr = -G (m1 + m2) / r2
My question is: Why is it possible to set a = v dv/dr = -G (m1 + m2) / r2 ?
On the left side there are units of acceleration (m/s^2) and on the right side is the gravitational force (kg*m/s^2). Shouldn't the units at all time be the same on both sides?
Thanks very much for an answer.
Regards, Philipp