Will 24 frames become 60 frames? Why?

This situation will not come out of the box.

If the original video is 24 frames and the video duration is 10 second, the total * * * is 240 frames. Change it to 60 frames, and the 240 frames will only be played for 4 seconds. The total number of frames will not change, and the frames will not be chaotic, just affecting the speed change.

Forcibly changing the frame rate will lead to speed change, so it will affect the duration. Usually changing the frame rate means recording a high frame rate and then changing it to 24 frames to achieve the effect of slow playback.