Topic 2 Flashcards
In distance time graphs what does the gradient mean?
The gradient means velocity
In distance time graphs what does a negative gradient mean
Returning back to start point
In d t graphs what does a horizontal gradient mean
The object isn’t moving
What does a curved line mean in d t graphs ?
the velocity is changing
In v t graphs what is the gradient
Acceleration
In v t graphs what is a negative gradient
Deceleration
In v t graphs what does a horizontal line mean
Constant speed
How to use light gates part 1
Set up two - one at start one ay end
Measure distance between them
When the object passes through the gates will measure the time taken for it to cross them
How to use light gates part 2
Then use speed = distance = time
Why is light gates more accurate than stopwatvhes
The light gates remove reaction time and human error
What is newtons first law
An object in motion has a constant velocity unless acted on by a resultant force
What is newtons second law
Force = mass x acceleration
What is intertial mass
A measure of how difficult it is to change the velocity of an object
Inertial mass = force ÷ acceleration
What is newtons third law
Every action has an equal and opposite reaction
Momentum
In kgms
Momentum = velocity x mass
Momentum is always conserved in a collision
Total Momentum before = total Momentum after
Force = change in Momentum ÷ time
What is Human reaction time
When there is a delay between a human observering an event and the human acting
What is the ruler experiment
When a person holds a ruler above their partners hand
They drop it randomly and records at what measurement the partner caught it
What is the average humans reaction time
0.25 seconds
What is thinking distance
How far you travel before you react
X metres
What is stopping distance
Then you reach causing the car to slow down and stop
Y metres
Factors affecting thinking distsnce
Tiredness
Influence of drugs or alcohol
Concentration
Factors affecting stopping distance
Speed
Poor road conditions(wet or icy)
Mass
What is the dangers of large decelerations in cars
When a car crashes a large deceleration happens over a short amount of time
The large deceleration causes a great force to be exerted on the car and passengers
