AP Physics C: Mechanics / Unit 1: Kinematics
1.1 Scalars and Vectors
Notes
- Scalars have size only: distance, speed, mass, time.
- Vectors have size and direction: displacement, velocity, acceleration, force.
- In one dimension, the sign (+ or −) shows direction.
Practice
Which is a vector?
It has a direction.
A car moves 5 m east then 3 m west. Its displacement:
$5-3$ in the east direction.
The total distance for that trip:
Distance adds all path lengths.
$\vec A=3\hat i+4\hat j$. Its magnitude:
$\displaystyle \sqrt{9+16}$.
Ready for more? Take the Unit 1 test.