THIS IS A PARREL CIRCUIT! Please help

Earthplanet yplanet y5=earth     *many different equationsplanet x1.5=earthplanet x is two times planet yobject 5,2500 mass5,1,3,2,4object 1 is four times obect 4

Two cars collide, lock bumpers and move together after the collision.this collision is known as perfectly inelastic collision.

Answerit decreases;