Kinematics & Football
And he is before all things, and in him all things hold together.
Colossians 1:17
What is Kinematics?
fr fr?
- How things move
- measures the positions, speed or velocity, and acceleration of objects.
Displacement
Distance
- Positive scalar quantity
- "how far"
- Gabe ran 30 meters to Stevens house and then curfew hit, so he ran 30 meters back home. His total distance was 60 meters.
- Vector quantity
- Change in position involving direction
- "how far from the starting point"
- In the same example with Gabe, his total displacement would be 0 meters because he ended up where he started. If he would not have gone home, his total displacement would have 30 meters in whatever direction he ran.
Velocity
Speed
- how fast something moves in a certain direction (vector)
- velocity (v) = displacement = d
time t
- Moving forward is positive
- backward is negative
- the rate of motion (scalar)
- speed (v) = distance = d
time t
- always positive
- If a problem is asking for how fast something is moving then solve for speed.
Acceleration
- Vector
- The rate at which speed/velocity changes over time.
- speeding up or slowing down
- a = change in speed = vf - vi
time interval t
vf= final velocity
vi= initial velocity
example:
While drag racing out
of our school parking
lot, I time myself at
a speed of 40 m/s 7
seconds after
starting.
What was my
acceleration?