3.Motion Flashcards
What is acceleration?
The rate of change of velocity.
Define average speed.
Distance over time for the entire region of interest.
What is braking distance?
The distance travelled between the brakes being applied and the vehicle coming to a stop.
What factors affect braking distance?
It is affected by the vehicle and road conditions.
Define displacement.
The direct distance between an object’s starting and ending positions.
What type of quantity is displacement?
It is a vector quantity and so has both a direction and a magnitude.
What does the gradient of a displacement-time graph represent?
The velocity.
What do curved lines in displacement-time graphs represent?
Acceleration.
What is free-fall?
An object is said to be in free fall when the only force acting on it is the force of gravity.
Define instantaneous speed.
The exact speed of an object at a specific given point.
What is projectile motion?
The motion of an object that is fired from a point and then upon which only gravity acts.
When solving projectile motion problems, what is useful to do?
Split the motion into horizontal and vertical components.
What is reaction time?
The time taken to process a stimulus and trigger a response to it.
What factors affect reaction time?
It is affected by alcohol, drugs and tiredness.
Define stopping distance.
The sum of thinking distance and braking distance for a driven vehicle.
What is thinking distance?
The distance travelled in the time it takes for the driver to react.
What factors affect thinking distance?
It is affected by alcohol, drugs and tiredness.
What do velocity-time graphs show?
How velocity changes over a period of time.
What does the gradient of a velocity-time graph represent?
Acceleration.
What do curved lines in velocity-time graphs represent?
Changing acceleration.
Define velocity.
The rate of change of displacement.
What type of quantity is velocity?
It is a vector quantity and so has both a direction and a magnitude.
