AP Physics KA

scalars

• quantities that only measure magnitude

• numerically positive

vectors

• quantitative measurements that encompass both direction and magnitude

• numerically positive or negative

vector notation

• an arrow above a quantity, indicating its direction

How are positive and negative values assigned to the direction of a vector quantity?

• If all values that represent the vector quantity fall within the same dimension, the positive and negative values must be determined by a coordinate system

Length of an arrow in vector notation

• indicates relative magnitude

tip or head of the vector

• arrow portion

tail of a vector

• the back end, opposite the direction

If vectors move anywhere in space…

• They do not change, as long as direction and magnitude remain constant

Ways vectors can be expressed

• (value), left/right

• (value) ←/ →

• - / + (value)

The sum of two vectors

• Resultant

• If two vectors have the same direction, the sum of their magnitudes is the resultant

Visually, how are vectors added?

• Tip-to-tail

• the tip of one vector attaches to the tail of the other

How do you add vectors visually, in second and third dimensions?

• tip-to-tail

When can a vector be subtracted from another?

• If two vectors have opposing directions, the difference can be taken by adding the negative vector to the positive vector

How to subtract vectors, visually

• tip-to-tail

Adding two vectors of different values (units)

• Like scalar quantities, the sum of two different values is meaningless

• Only add/subtract like terms

“Position” measures

• location, relative to a coordinate system, distance and time