Brain Test Level 171 Poor crow is unable to eat the walnut

Daze Puzzle provides a complete walkthrough for "Brain Test Level 171: Poor crow is unable to eat the walnut.".

By Daze Puzzle /
Level 171 in other versions:
Question
Poor crow is unable to eat the walnut.
Hints
Hint 1:
That rock looks quite hard enough to break the shell.
Step 1
Step 2
Answer
Take the walnut up to the air and drop it on one of the rocks to break it. Then feed the crow.