if a missile is fired from a tank it gets a momentum of 2000 kg metre per second if the velocity of the Missile 50 metre per second what will be its mass

40kg

Explanation:

Given parameters:

Momentum of the missile  = 2000kgm/s

Velocity of the missile  = 50m/s

Unknown:

Mass of the missile  = ?

Solution:

Momentum of a body is the amount of motion a body posses. It is mathematically defined as the product of mass and velocity;

     Momentum  = mass x velocity

The unknown is mass, insert the given parameters and solve for it;

     2000 = mass x 50

       mass =   = 40kg

i think the answer is a, hope this is right, that would be my best guess.

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.