Showing my age here...
I grew up with the Silver Age Flash (70s-80s)
The Flash has no super-strengh, per say, but he is invulnerabe to the effects of his super-speed (no friction burns, super-fast reflexes, super-fast thinking)
Person holding on by fingertips. 1. Like TEEEEEEEJ said, he could size up the situation, find all the materials he needed and save the person. 2. He could get under them and run up the side of the cliff and pick them up on the way(He is so fast that he can easily overcome his own body's falling momentum as well as several other people's, as well). 3. He could generate a strong enough upward draft to push the person back up over the cliff.
Teetering house..1. He would be fast enough to clear the house before the his added weight could actually make the house fall. 2. (see #3 above)
Tank could probably give you even more examples.
James
