2. In recoil __ Choose all correct answers. D objects always have the same mass D the total momentum before and after is the same kinetic energy is conserved D momentum is conserved D objects always have the same velocity

## Step 1<br />The problem is about the principle of conservation of momentum, which is a fundamental concept in physics. The principle states that the total momentum of a system remains constant if no external forces are acting on it.<br /><br />## Step 2<br />The first statement, "objects always have the same mass", is not necessarily true. The mass of an object can vary depending on the context.<br /><br />## Step 3<br />The second statement, "the total momentum before and after is the same", is true. This is the essence of the conservation of momentum.<br /><br />## Step 4<br />The third statement, "kinetic energy is conserved", is not necessarily true. While kinetic energy can be conserved in certain situations, such as elastic collisions, it is not always conserved.<br /><br />## Step 5<br />The fourth statement, "momentum is conserved", is true. This is the principle of conservation of momentum.<br /><br />## Step 6<br />The fifth statement, "objects always have the same velocity", is not necessarily true. The velocity of an object can vary depending on the context.