A spark occurs at the tip of a metal needle if the electric field strength exceeds 3. 0×106 n/c, the field strength at which air breaks down.

hail is a solid form of precipitation composed of large, layered ice particles called pellets that often have spherical shapes. this phenomenon occurs during thunderstorms in the could type known as cumulus

hope this you out ^w^

not too sure thinking it will always be directed towards the centre of the earth. could be wrong not sure

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.