A1.2 kg block slides along a frictionless surface at 1.2 m/s . a second block, sliding at a faster 4.4 m/s , collides with the first from behind and sticks to it. the final velocity of the combined blocks is 3.2 m/s .

2.0 kg

Explanation:

For a closed system, the momentum is always conserved. Momentum of an object is given by mv where m is the mass and v is the velocity.

Momentum of the system before the collision is given by:

Momentum of the system after the collision is given by:

Mv where M is the combined mass of the 2 blocks as they stick together and v is the velocity.

As the momentum is conserved i.e momentum before collision and after collision is the same:

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.