answersLogoWhite

0

Scalars are quantities that have magnitude only; they are independent of direction. Conversely, vectors have both magnitude and direction.

A scalar quantity is any numeric value that has no spatial direction. So let's look at your four tests.

  • Time. We can give it a numbers; so it qualifies as a numeric value. Can it have spatial direction? No. It marches on, but in no direction. Saying 2 minutes south, for example, makes no sense whatsoever. So it's a scalar quantity.
  • Speed. Again with the numbers...25 mph for example. But can it have a direction. Yes. 25 mph heading north makes sense; and because it also has direction it is not a scalar but a vector; when speed has a direction it is called Velocity. Note: all vectors will have a scalar component, but not all scalars will have direction.
  • Position. This is tricky. What is the numeric value of position? Distance...25 miles, for example, gives us an interval in space. Can this interval have spatial direction? Yep. 25 miles north of my house, for example, gives the direction of the interval. But like velocity, if we leave off the direction, we are left with the scalar...25 miles. In fact, position and velocity are related. If I divide the 25 miles north by 1 hour interval in time to travel to that position, I'd have 25 mph north...the previous velocity.
  • Acceleration. We can assign numbers, like 9.81 m/s²; so without direction, it is a scalar. Does assigning a direction make sense? Sure. Braking at 4 m/s² in a westerly direction makes perfect sense. So, with its direction added, acceleration can be a vector just like position and velocity. In fact, the three are related, which is why they are all three capable of being vectors.
User Avatar

Wiki User

9y ago

What else can I help you with?