One of my jobs this week has been to take Crawf Minor to University for his Natural Sciences interview.

They sent this bouncer down the pitch to him:

You have a long steep icy slope. Two cylinders are at the top of the slope. One rolls down, one skids down. They leave at the same time. Which gets to the bottom faster? Oh, and explain why.

He thinks he nailed this one at least. Any smart readers care to offer a view?