## Units and measurements

You simulate physics, so scale and dimensions matter. Your carrot is scaled down to 0.1, yet it measures over 8 meters long, and its rigid body mass is 1 kg.

First, set your carrot dimension to a more reasonable dimension, like 15-20cm long. Scaling it to 0.002 gives you a 16cm carrot.  
Then, Apply the scale using <kbd>&#9096; Ctrl</kbd><kbd>A</kbd> > Apply Scale so that the current dimension of the carrot is the normal "1" scale.  
Then in the rigid body settings, set the carrot's mass to something more like a carrot, like 200g.

Don't forget to do this on your carrot model, and also on your other collision objects.

Then move your carrot closer to the ground because it is otherwise three stories high, and the simulation should work just fine.

## Collision objects

Just a personal preference but I am not a big fan of the compound parent system in Blender, I find it way more reliable to either use the other options or use one parent object modeled specifically for the physics simulation.

The only reasons you would want to use a different object for controlling the physics is for performance and customization: using a different mesh allows you to go lower in mesh density and avoid convex shapes, which is easier to calculate, and also abstract some aspects of the simulation like artificially inflating/deflating the collision mesh in some areas to make other objects meet at the right point.

Here I made one using a duplicate of your carrot, removed everything but one edge loop, and extruded a few times. Set it as parent, removed the physics settings from the carrot and put it on the collision object instead:

[![enter image description here][1]][1]






  [1]: https://i.sstatic.net/t4BIT.png