Read the scenario and choose the correct answers.
Imagine you have just witnessed a small avalanche on a mountain while skiing, and two slushy snowballs just
crashed together in a perfectly inelastic collision. They are moving as one larger snowball, as a combined mass.
Before the collision, snowball A was 7 kg and had initial momentum of -14 kg · m/s; therefore, its velocity must have
been m/s.
Snowball B had initial momentum of 15 kg. m/s, and a velocity of 5 m/s; therefore, its mass must have been kg.
Recognizing that momentum is conserved in inelastic collisions, the total momentum of the combined snowballs after
the collision must be kg. m/s.

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.

grav forces affect all objects magnetic forces affect magnetic objects and electric currents