Question: [How does conservation of momentum change in moving frames ( constant velocity ) and non-inertial frames?](https://physics.stackexchange.com/questions/545950/how-does-conservation-of-momentum-change-in-moving-frames-constant-velocity)

In this question's accepted answer, it says that if the time period of application of pseudo force is negligible, then the conservation of momentum holds. But I have learnt that momentum is always conserved? Where does this aspect of time period come into the picture?

Answer: 
The 'solution' makes essentially zero sense. Indeed, it's of the *not even wrong* variety.

(0) A resistor is only a 'fuse' in the sense that it will overheat and perhaps smoke before opening up if the power dissipated is well above the power rating for some time. But there's no mention of the power rating of this resistor 'fuse' so there's not enough information given to even make a guess at what current would cause it to open up.

(1) The calculation for the 5A maximum current calculation assumes the full 240V is *dropped* across the 48 ohm resistor 'fuse'. Why? Consider that it could only be a 'fuse' if it's in series with the load (a fuse protects a circuit by becoming an open circuit). But if it's in series with the load, it would have the full 240V across only if the load has *zero* volts across. But globes with zero volts across have *zero* current through! The 5A current calculation makes zero sense in this context.

(2) The calculation for the current through a single globe assumes the entire 240V is across the globe. But, if there's a 48 ohm resistor 'fuse' in series, the globe current is through that resistor which means that the voltage across the globe is *less* than 240V. Which means the calculated current isn't relevant to this problem.

(3) The problem statement mentions that the globes are in series but clearly, only when the globes are parallel connected do we add their currents.
The teacher is wrong. Not even wrong. In a very embarrassing way.

You should complain to his supervisor if he is not willing to accept his mistake.