So If I'm falling at a rate of five meters per second, and the ground is... <Some number> below me then...
I grab onto a piece of plastic large enough to slow my fall to non-lethal levels.
Wooo! Math is so much easier when I know all numbers.
“She'd become a governess. It was one of the few jobs a known lady could do. And she'd taken to it well. She'd sworn that if she did indeed ever find herself dancing on rooftops with chimney sweeps she'd beat herself to death with her own umbrella.”
― Hogfather