g (gravitational field vector) (1 Viewer)

[velox]

how can we explain that g (gravitational field vector) can be measured in both ms^-2 and N kg^-1 ?
cheers

 

[archangel leila]

hmm never really thought about it, and can't really think of a worded explanation... but I know that for m/s^-2 and N/kg you're using the 2 known equations for acceleration (which is what gravitation is - acceleration of a mass in a field due to force)

a = change in v/ change in t
(this logically gives the rate of change of motion - velocity - for every second, giving m/s/s) ie how fast an object is speeding up per unit of time

F = ma
If you rearrange this, you get:
a = F/m
Using this equation, the units you get for the acceleration are derived from the units for the components in the equation:
ie F is measured in Newtons and mass is measured in kg
Inserting this into the equation, you get:
a = N/kg
So therefore acceleration due to the gravitational field is measured in Newtons per kg (N/kg) as well as the obvious metres per second, per second.
I guess it's a matter of using the equation F = ma and using the units of the components?

Hope that helps in some warped way, haha. Hmm don't really know of another explanation, so if someone can do this in a more comprehensive way, the floor is yours! (it'll help me too )

 

[saves.the.day]

how can we explain that g (gravitational field vector) can be measured in both ms^-2 and N kg^-1 ?
cheers

Just show by units of equations. i.e. Newtons 2nd law and looking at the units that define gravity.

F=m.g => g=F/m (N.kg^-1)
and
g=dv/dt (ms^-2)

 

[Xayma]

1N=1m*kg*s^-2
Therefore:

1ms^-2=1Nkg^-1

You should stick with ms^-2 since it is the simplest form.

 

[velox]

Nice Xayma. Thanks heaps