Chapter 3 - Motion Flashcards
Define speed.
Speed is defined as the rate of change of distance
Speed = Distance/Time
What is instantaneous speed?
Instantaneous speed is the speed of an object over a very short time interval. Find tangent to the point at given time.
Define velocity.
Velocity of an object is defined as the rate of change of displacement.
Velocity = Displacement/TIme
Define acceleration.
Acceleration is defined as the rate of change of velocity.
Acceleration = Velocity/Time
What are the SUVAT equations?
S-Displacement U-Initial Velocity V-Final Velocity A-Acceleration T-Time v = u + at s = (u+v/2) x t v^2 = u^2 + 2as s = ut + 1/2xaxt^2 Must be separate into x and y.
What techniques can you use to investigate motion?
- Light gates and data logger.
- Linear air track.
- Trap door, for free fall.
- Camera, using the frame to calculate time.
What is stopping distance and how is it effected?
Stopping distance is made up of thinking distance and braking distance.
Thinking distance- Distance from when hazard occurs and when he brakes are applied.
It is effected by alcohol and age.
Braking distance- Distance from when the brakes were applied to when the car stopped.
It is effected by road conditions, weather and car conditions.
Define displacement?
Displacement is how far an object is from its original position, in a given direction. Regardless of the route taken.
How do you work out SUVAT for projectile motion?
- Split into horizontal and vertical motion.
- We assume there is no horizontal acceleration, and that time is constant between both X and Y.
When force acts at an angle, how can we resolve it to X and Y?
Horizontal- Fcosø
Vertical - Fsinø
Where ø is the angle to the horizontal.
What are the key features of a displacement time graph?
- Gradient is the Velocity.
- If gradient is curved, then the object is accelerating.
- Instantaneous velocity can be found by a tangent to the curve at a point.
What are the Key Features Velocity-Time graphs?
- The gradient is the acceleration.
- Displacement is the area under the graph.
- ## A curve represents a changing acceleration.
How can the factors effecting motion be investigated by a trolley?
Motion down a slope can be instigated to see the effect of the angle of the slope, mass of the trolley, shape of the trolley, or how friction effects the motion.
How can a camera be used to measure the time taken for an object to travelled past a point?
Time taken = (Number of frames till trolley passes a point) / Frame rate of camera.
