Kinematics in Two Dimensions; Vectors

Kinematics in Two Dimensions; Vectors

Vector: 

A quantity that has magnitude, size, and direction. Velocity and displacement are examples.

Scalar: 

A quantity that has only magnitude, or size.  Speed, distance, and time are examples.

Vector Addition:

When vectors are graphically added, they are drawn head to tail.  This may also be described as placing the arrowhead of one vector next to the tail end of another vector.

Resultant:

• The result of adding two or more vectors; vector sum.  It is drawn from the tail of the first vector to the tip of the last vector.

Phythagorean Theorem:

• c2=a2+b2

Vector Component:

• The parts into which a vector can be separated and that act in different directions from the vector.

Horizontal Motion of a Projectile:

Since gravity acts only vertically, there is 0 acceleration.
Horizontally, the projectile moves with a constant speed.
We can use one of the previous kinematic formulas  v=d/t

Vertical Motion of a Projectile:

Use previous kinematic formulas in the vertical direction.
a = Δv/Δt=(vf-vi)/t
d=vit+at2/2
vf2=vi2+2ad
acceleration due to gravity = -9.8 m/s2