What would be harder to accelerate- a 4kg shot put ball or a 2,000 kg boulder

Explanation:t

The Inertial is the resistance of a body at rest to be in motion

Given the following  item

1. 4kg shot put ball  

2. 2,000 kg boulder

The body of greater mass has greater inertia, hence would be harder to accelerate.

An object with a small inertial mass will accelerate more than an object with a large inertial mass when acted upon by the same force.

Of the 2 items in the list, the 2,000 kg boulder has the largest mass, hence it also has the greater inertial  and more difficult to accelerate.