Distance, Speed And Acceleration (work And Energy) Flashcards
Speed equation
Speed = distance ÷ time
Stopping distance equation
Stopping distance = thinking distance + breaking distance
What is thinking distance
Distance travelled while thinking about breaking
what is breaking distance
The distance travelled after breaks have been hit
What factors affect thinking distance
Tiredness, drugs, alcohol, distractions, speed
What factors affect breaking distance
Road quality, tire quality, engine quality, break quality, speed, weather
What is Acceleration and deceleration
Acceleration is an objects change in speed (positive)
Deceleration is an objects change in speed (negative)
What is the unit for :
-Acceleration
-Deceleration
M/s(squared)
M/S(-squared)
In a distance time graph what does a shallow/steep curve mean
Steep: fast
Shallow: slow
How to calculate the gradient of a graph
Gradient= rise ÷ run
What does a horizontal line mean on a velocity time graph?
what if its value is 0 on the velocity axis?
-Constant velocity
-Stationary
What is Newton’s first law
If an object is at rest it stays at rest, if an object is in motion it moves with a constant velocity unless acted upon by an external force
Force equation
F=ma
Force = mass x acceleration
What is Newton’s second law
The force acting upon an object is equal to the mass of that object times its acceleration
(F=ma)
Newton’s third law?
For every action there is an equal and opposite reaction
What is force measured in
Newtons (N)
What are the directions of forces
Gravity, friction, thrust, air resistance (drag), upward thrust, weight
An example of Newton’s third law
Table pushes upwards on book, book pushes downward on table
Difference between weight and mass
Weight is the force of gravity, acting on an object its measured in newtons
Mass is the amount of matter in an object and its measured in kilograms
Terminal velocity
When both forces are equal and opposite
What is hookes law
The extension is directly proportional to the stretching force
Elastic limit?
If a spring is taken beyond its limit, it will not return to its original shape
Hooked law equation
F=Kx
Force applied (N) = spring constant (N/cm) x extension (cm)
Elastic potential energy:
Epe = 1/2 x F x X
1/2 x force x extension
(Area under graph)
Work done equation
Work done = force x distance moved in direction of force
How to find spring constant
Force
———-
Extension
