I'd be surprised if this hasn't been asked before, but I couldn't find it. In the awesome TV show Stargate: SG-1, I've noticed that how one exits the Stargate is inconsistent. Several times we witness someone - usually the SG-1 team - walk through the gate normally on the Earth side, but then come tumbling out on the exit side.
In-universe, it's been stated that an object in motion maintains its velocity and momentum when traveling through the gate, so tumbling out of the game makes sense when you originally jump or leap into it (as the team often does when in danger). However, if you walk in one side, you should come walking out the other side - as is shown more than half the time.
I originally thought maybe they tumbled out the exit gate due to the ramp at SGC being higher on the event horizon then the platform on the exit gate, but we've also seen the opposite - SG1 (or someone) walks or runs through the off-world gate and comes tumbling out on the Earth side.
Note that the spin-off series - Stargate: Atlantis - appears to be far more consistent regarding how one enters and exits the gate.
Is this inconsistency in SG-1 merely used for dramatic effect, or is it explained in-universe?