145 Grams!
It asks for the “Total Mass” basically asking to add, If you add 20 to 125, you get 145! Correct me if im wrong
The initial momentum of the system can be expressed as,

The final momentum of the system can be given as,

According to conservation of momentum,

Plug in the known expressions,

Initially, the second mass move towards the first mass therefore the initial speed of second mass will be taken as negative and the recoil velocity of first mass is also taken as negative.
Plug in the known values,

Thus, the final velocity of second mass is 2.99 m/s.
Answer:
because it can be hard
Explanation:
I said that because they be on bed rest
According to the statement " Collision <span>between two bodies in which the total kinetic energy of the two bodies after the collision is equal to their total kinetic energy before the collision."
The best answer is :
Option A " </span><span>BODY A COMES TO REST BODY B STARTS MOVING WITH INITIAL VELOCITY OF BODY A "</span>