According to the solar nebular theory, a supernova triggered the collapse of a nebula, which began the formation of clumps of gas and dust. according to the solar nebular theory, these clumps most likely became the

a. milky way and comets
b. sun and planets
c. asteroid belt
d. galaxies

thermal energy is the answer

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.