I had this discussion with someone about the difference between matter and mass and I want to know if I'm on the right track (I'm new to science).
yeah, what I'm seeing is that they're talking about the same thing but matter refers to the actual thing (the substance) and mass is the way we measure that thing (property). That's why it seems circular. I think this because they're now talking about density. The definition is the amount of mass compared to its volume. volume is occupied space by an object. So we can have two things with equal volume but different mass. Meaning, volume is a way to measure occupied space (property) but not matter. Mass measures matter. And density measures matter given space. So everything is just properties except for matter. What I'm getting at is (if you read up to here thanx) that mass, volume and density are things we use to talk about matter. I hope I'm getting this.
Speed vs Velocity
"It is important to understand that the magnitude of velocity (speed) does not determine if something is accelerating."
Average speed = (total distance)/(total time)
Average velocity = (total displacement)/(total time)
Clearly, we can get different numbers of average speed and velocity for an object that moved. Then why is speed the magnitude of velocity? Unless they're only different when we talk about averages. I'll go with that. An object moves up and down with a displacement that forms a triangle (using vectors). The object has only one average velocity < only 1 average speed but it has 2 speeds whose magnitude are equal to their respective velocities (pictures would be nice but I don't know how to do that here).