C3 (Motion) Flashcards
Average speed equation
Total Distance travelled/ total time taken
What does the gradient in a distance time graph represent
Speed
Instantaneous speed
Is the speed of the car over a very short interval of time
How to find instantaneous speed
Draw a tangent at the point
The gradient is the instantaneous speed
Equation for average velocity
Change in displacement/ time taken
In a displacement time graph what does the gradient represent
Velocity
Acceleration definition
The rate of change of velocity
Acceleration definition
a= change v/ change t
What does the gradient of a velocity time graph represent
Acceleration
What does the gradient of a velocity time graph represent
Acceleration
How do u find the displacement of a velocity time graph
Area underneath the graph
Stopping distance
The total distance travelled between the moment when you first see a reason to stop, to when the vehicle CK es to a stop
Thinking distance
The distance travelled between the moment you first see a reason to stop, to the moment you apply the brakes
Braking distance
Distance travelled from the time the brake is applied until the vehicle stops
Many factors influence these distances
Speed of vehicle Condition of brakes Tyres Road Weather conditions Alertness of the driver
Equation of thinking distance
Speed x Reaction time
Free fall definition
When an object is accelerating under gravity, with no other forces acting on it, it is said to be in free fall
What does the value of g depend on
Altitude
Latitude
Geology of an area
What are three different ways of measuring the value of g
Electromagnet and trap door
Light gates
Taking pictures
Projectile motion, assuming that there is no air resistance, what can be stated?
The vertical velocity changes due to acceleration of free fall
The vertical displacement and time of flight can be calculated using the equations of motion
Horizontal velocity remains constant
What are the two types of friction
Contact and fluid friction
How does an increase in speed affect the value of friction
It also increases
What can the force friction never do
Speed things up or start something moving
What does friction convert kinetic energy into?
Heat
What decreases terminal velocity
The SA of the falling object
A moment
Is the turning effect of a force
What does the moment or torque depend on
Force being applied
And it’s distance from the pivot
Moments must be balanced or…
The objects will turn
Sum of clockwise moments = sum of anticlockwise moments
Muscles, bones and joints all act as what?
Levers
What is a couple
Pair of forces of equal size which act parallel to each other, but in opposite directions
What does the torque depend on
The size of the forces and the distance between them
