I am trying to understand net force intuitively and this is what I think.
If a net force is towards the positive $x$ direction, which of the following is true ?
a) It can be moving in the negative $x$ direction
b) It can be speeding up
c) It can be slowing down
d) It can be moving in the positive $y$ direction
a) No, because if an object is moving towards the left, $x_f-x_i$ is negative, so the velocity is negative as well as the acceleration. So, impossible.
b) Yes. as a matter of fact it has to because positive acceleration means speeding up.
c) No. Same reason as b.
d) No, because the y-direction is perpendicular to the x.
I got this problem wrong and I don't think I am really understanding acceleration. Can someone help me out ?