Tell me Physics facts!

Something with a constant speed can accelerate whilst it's speed stays constant.

the word physics originates from the greek word for nature

That's interesting. How does that work?

That's cool, I love learning the origin of words

acceleration is the change in velocity (which is a vector), so if you change direction you can accelerate while still having a constant speed (speed is a scalar and only has magnitude)

no problem

That's interesting. How does that work?

Notice I said speed. If an object rotates in circular motion about a fixed point with it's speed constant, it's vector velocity constantly changes as it's direction of motion constantly changes. An acceleration is the rate of change of velocity with respect to time therefore there must be an acceleration. This acceleration is towards the centre of the circle, the object obeys Newton's first law in the sense that it 'tries' to keep moving in a straight line, but there is a net force on that object due to it's mass and acceleration, F=ma. Therefore it moves in a circle because the force is always perpendicular to it's vector velocity and directed towards the centre.

Electrons have act as if they have no mass in carbon sheets (e.g. graphite)
http://physicsworld.com/cws/article/news/2005/nov/09/electrons-lose-their-mass-in-carbon-sheets