Let us remember that the magnitude of acceleration due to gravity on the both objects is exactly the same.
However, the mass of the objects are different. Mass is a measure of the inertia (resistance to motion) of a body. The greater the mass, the greater the inertial. The boulder has a greater mass and hence a greater inertia (more resistance to motion).
Therefore, the boulder will have less kinetic energy
The reaction of 1-bromo-2-methylpropane (isobutyl bromide), , with , and results in the formation of an adduct of formula known as grignard reagent, an organometallic reagent, which on reacting with results in the formation of isobutane.