The phrase "a practical explanation for" is correct and usable in written English.
It can be used when you want to provide a clear and useful reason or justification for something.
Example: "The scientist provided a practical explanation for the phenomenon, making it easier for the students to understand."
Alternatives: "a useful rationale for" or "a functional justification for".
There is a practical explanation for that.
The figurines "come from the grave anyway," she said, giving a practical explanation for her no-cleaning policy.
Perhaps that was true, but Mr. Sweet had a practical explanation for his interest in photographing these things.
Emily Kokal, singer and guitarist in the hottest new band of the moment, has a practical explanation for her band's many famous fans (actors Billy Zane and the late Heath Ledger among them).
The analysis showed that the peeling mechanism is a practical explanation for the delamination of clay platelets during melt extrusion and that the dimensions of the clay platelet tactoids play an important role in the peeling due to the shear stress.
Lute had a more practical explanation for liking the image, a prism that doubled as her necklace in the still-to-be-released Beautiful Things video.
Along with the quips came a more practical explanation for the resilience of an artist who had long embodied flaming youth, beauty and an intellectual bon vivant milieu.
It is unfortunate that the one they are best known for all around the world is those prolonged yells of 'goooooool.' This, though, has a practical explanation.
The noose seems to have held fast, though when asked now, Mr. Lawrence offers a more prosaic and practical explanation for why he has stayed in Alcoholics Anonymous and stayed away from drinking so long -- in fact longer than he has in decades.
The practical explanation for her decision to join seems to be that she wished to help the African nationalists and was determined to change the situation in Southern Rhodesia, if no longer in the world as a whole.
