I have some questions about acceleration that I'd like for someone to explain to me. As far as I know, acceleration depends on either change in velocity or change in direction (or both). So if I'm going 1m/s North constantly I'm not accelerating. However, what would be the acceleration if I walk 1m/s North, turn sharply 90 degrees to the West whilst maintaining my velocity at a constant 1m/s? What would the magnitude and direction of that acceleration be? Why is it so that acceleration happens when you simply change the direction of a given velocity? Is it possible for an object to maintain a certain velocity and change direction? Why is it so that an object has an inward acceleration if it has a constant velocity going in a circle? What is "acceleration" if there's no change in velocity, and why is it taken into account? I'm a beginner, so try to keep your answers easy to understand.