Unsolvable Puzzle: Can a Puck Stop in 0.42s?

[chengbin]

Homework Statement

A puck of mass 30g slides across rough ice, experiencing a frictional force of 0.2N. If it was moving at 10km/h when it hit the ice patch, how long did it take to stop? How long was the ice patch?

Homework Equations

The Attempt at a Solution

I don't think this question is solvable or make any sense. If it hits something, it stops instantly, but the answers say 0.42 seconds.

 

[tiny-tim]

Hi chengbin!

This is colloquial English …

"hit" (here) means "reach" … it reaches the ice patch, and is slowed down while crossing it.

(see http://en.wikipedia.org/wiki/Colloquialism" )

 

[chengbin]

Hi chengbin!

This is colloquial English …

"hit" (here) means "reach" … it reaches the ice patch, and is slowed down while crossing it.

(see http://en.wikipedia.org/wiki/Colloquialism" )

Thank you!

That solved the problem.