Acceleration and Equations of Motion Flashcards
acceleration
change of velocity per unit time
acceleration equation
(v-u)/t
What is a method of measuring acceleration?
single card 2 light gates computer measure velocity of each light gate and time between
measuring distance travelled on graph
total area under speed-time graph
measuring displacement on graph
total area under velocity-time graph
Describe this velocity-time graph.
accelerates for 10min constant velocity of 60m/min for 5min decelerates for 15 mins accelerates for 10 mins in opposite direction decelerates for 15 mins
derive v = u + at
- a = (v-u)/t
- v = u + at
derive s = ut + ½at²
- s = vt
- replace v with average velocity s = ((u+v)/2)t
- subsititue in v = u + at
- s = ½(u + (u + at))t
- s = ½(2u + at)²
- s = ½(2ut + at²)
- s = ut + ½at²
derive v² = u² + 2as
- v = u + at
- t = (v – u)/a
- s = ½(u + v)((v – u)/a)
- s = ((v + u)(v – u))/2a
- 2as = (v + u)(v – u)
- 2as = v² – u² v² = u² + 2as
derive s = ½(u + v)t
- average velocity = (u + v)/2
- s = ((u + v)/2)t
- s = ½(u + v)t
deceleration
acceleration decreases (negative acceleration)
any object freely moving through the air is… towards the ground under the influence of…
accelerated gravity
what does gravity provide?
doward acceleration of 9.81m/s^2
what happens the instant an object is dropped?
stationary so u = 0m/s
what is the accleration of a dropped object?
-9.8m/s^2