Module 3.1 Flashcards
Acceleration
The rate of change of velocity
Average speed
Distance over time for the entire region of interest
Braking distance
The distance travelled between the brakes being applied and the vehicle coming to a stop. It is affected by the vehicle and road conditions
Displacement
The direct distance between an object’s starting and ending positions. It is a vector quantity and so has both a direction and a magnetitude
Free-fall
An object is said to be in free fall when the only force acting on it is the force of gravity
Instantaneous speed
The exact speed of an object at a specific given point
Projectile motions
The motion of an object that is fired from a point and then upon which only gravity acts. When solving projectile motion problems, it is useful to split the motion into horizontal and vertical components
Reaction Time
The time taken to process a stimulus and trigger a response to it. It is affected by alcohol, drugs and tiredness
Stopping distance
The sum of thinking distance and braking distance for a driven vehicle
Thinking distance
The distance travelled in the time it takes for the driver to react. It is affected by alcohol, drugs and tiredness
Velocity time graphs
Plot showing how velocity changes over a period of time. The gradient gives acceleration. Curved lines represent changing acceleration
Velocity
The rate of change of displacement. It is a vector quantity and so has both direction and a magnitude.
How can Instantaneous speed on a distance time graph
Find the gradient at a given time
On a displacement-time graph what does a flat line, straight line and a curved line represent
stationary object, constant velocity, acceleration
What are the types of equations needed for linear motion
SUVAT equations
What is needed to calculation project motion
No air resistance
How do you calculate projectile motion
SUVAT in horizontal direction, acceleration is zero so U = V
SUVAT in vertical direction
a = g
time is equal for both
How to find the horizontal distance of a projectile motion
Find time where the ball hits the max height using vertical SUVAT
time is equal to time in the horizontal direction
Use horizontal SUVAT to find S and the times it by 2 because it is symetrical
How to find the final velocity of a object under projectile motion
Resolve the resultant velocities in both planes
This will lead to a final component with horizontal and vertical velocities.
Using these, sub into Pythagoras theorem to get the final velocity
How is thinking distance related to initial speed
thinking distance is proportional to speed
How is breaking distance related to initial speed
thinking distance is proportional to speed squared
why is breaking distance related to initial speed
For car to stop, Kinetic energy = 0
Kinetic energy = 1/2 (mv^2)
since mass is constant:
Kinetic energy is proportional to velocity^2
