The 'force' in this formula is the 'net' force on an object ... the combined result of all the forces acting on it. If the net force is zero ... either there are a bunch of forces but they all cancel each other and add up to zero, or there's actually no force at all acting on the object ... then it's clear from that simple formula that the acceleration must also be zero. My personal opinion is that the statement in (1) is true.
(2). The components of a big vector are two little vectors that add up to be equal to the size and direction of the big vector. If they didn't both have size and direction of their own, then they couldn't add up to be a vector. So each component must be a vector.
(3). This one is so simple that it's hard to explain. If you and your big sister are both pulling on a book ... you're pulling that way /\ and she's pulling that way >, the only way for that book not to move is for both of you to pull with zero force. If either of you pulls with any force, then the book must move. The components of a vector are perpendicular, like those arrows that I tried to draw. The only way the whole vector can be zero is if both components are zero.
I’m slightly confused about the wording of the question but if both the same y-intercept that means both company’s have the same flat rate charge for artwork.
