[Physicist]

I'll second this - most of my students didn't even have a clue as to what friction is.

I don't expect an incoming student to know what friction is. I had to train myself to stop expecting that they know what sines and cosines are, beyond too-convenient buttons on their calculators. A problem like, "there's a 10-foot ladder propped at a 60-degree angle against a house; how high does it reach?" is quite beyond most freshmen.

[RadioAstronomer]

"there's a 10-foot ladder propped at a 60-degree angle against a house; how high does it reach?" is quite beyond most freshmen.

Spooky :-(

[MacDorcha]

"A problem like, "there's a 10-foot ladder propped at a 60-degree angle against a house; how high does it reach?" is quite beyond most freshmen"

you mean side-angle-side? thats a 30-60-90 triangle, so lets see... 5 feet away from bulding... 10 cubed root... 8.6 something or other feet.... up