smashing fruit with rock - mini game

Hi, hoping someone can help! have been trying for hours to get through the mini game with Amber. cannot seem to break any of the fruit? have tried heaps of variations on the momentum etc, but it either flicks up & hits Amber, or says i am off center. Had a look at a walk though today (which only told me what i was already doing anyway, so no help), and getting very frustrated, as i cannot go any further until i get past this!
Any tips on doing this puzzle would be great! thanks

Hated this puzzle until I finally 'got it'... after a while, you should have a choice for an 'easy' mode... select it. Then, hit the fruit when your arm is 1/2 way... I had to just barely hit it to get the fruit.
There will be a quiet 'tap' noise if you get it right. I admit I had a bit of fun flicking nuts at the other monkey as well.

I've tried the arm 1/2 way and still can't seem to get the fruit to open. I've clicked then tried the double click in easy mode. Help

I've tried original & easy, get the same results, i.e., it hits Amber or says I'm off-center. I have tried time & again, for several (10+) minutes. Any more suggestions?

Also, I've gotten stuck at the part where Mina should be able to stop the disaster, but the coconut Jep put in the turbine hold disappears & I have nothing else in inventory that fits. HELP!