#### Transcript of Physics 5054 - Scalars and Vectors

**Understanding the difference**

**Scalars and Vectors**

a.Scalars are quantities that are fully described by a magnitude (or numerical value) alone.

b.Vectors are quantities that are fully described by both a magnitude and a direction.

To test your understanding of this distinction, consider the following quantities listed below. Categorize each quantity as being either a vector or a scalar.

a. 5 m

b. 30 m/sec, East

c. 5 mi., North

d. 20 degrees Celsius

e. 256 bytes

f. 4000 Calories

Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion.

Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

Distance and Displacement

Speed and Velocity

Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance.

Velocity is a vector quantity that refers to "the rate at which an object changes its position."

As such, velocity is direction aware. When evaluating the velocity of an object, one must keep track of direction. It would not be enough to say that an object has a velocity of 55 mi/hr. One must include direction information in order to fully describe the velocity of the object. For instance, you must describe an object's velocity as being 55 mi/hr, east.

Vector quantities are often represented by scaled vector diagrams. Vector diagrams depict a vector by use of an arrow drawn to scale in a specific direction.

There are several characteristics of these diagram that make it an appropriately drawn vector diagram.

a scale is clearly listed

a vector arrow (with arrowhead) is drawn in a specified direction. The vector arrow has a head and a tail.

the magnitude and direction of the vector is clearly labeled.

Representing Vectors

Full transcript