Topic 2 Flashcards
Acceleration Due to Gravity
The acceleration, g, experienced by an object travelling in freefall. Its value at the surface of earth is 10m/s²
Acceleration
The rate of change of velocity.
Braking Distance
The distance a vehicle travels under the braking force. This can be affected by adverse road conditions and weather conditions and the condition of the vehicle.
Centripetal Force
The resultant force that acts towards the centre of a circular path of an object travelling with circular motion.
Circular Motion
The motion of an object travelling in a circle. An object travelling in circular motion is always accelerating.
Why is an object in circular motion always accelerating?
Because of its continual direction change. This means centripetal force is always required.
Conservation of momentum
The total momentum of a system before an event is always equal to the total momentum of the system after the event.
Displacement
A measure of how far an object moves in a given direction. It is the straight line between the starting and finishing points in a vector quantity.
Distance
A measure of how far an object moves. It is a scalar quantity.
Free-Fall
Motion under the force of gravity alone.
Human Reaction Time
The time it takes for the brain to react to the stimulus.
Typical Human Reaction Time
0.2-0.9 Seconds
Inertial Mass
A measure of how hard it is to change an objects velocity.
What is Inertial Mass equal to?
Ratio of Force/Acce
Unit of Force
Newton
Newtons First Law
If an objects resultant force is zero the object will remain at a constant velocity.
Newtons Second Law
An objects acceleration is directly proportional to the resultant forces acting on it, and inversely proportional to the objects mass .
Newtons Third Law
The forces that two objects exert on each other when they interact are equal and opposite
Resultant Force
The single force that can replace all the individual forces acting on an object and have the same effect.
Scalar Quantities
Quantities that only have a magnitude.
Speed
A measure of change in distance.
Scalar Quantity
Speed =
Distance/Time
Stopping Distance
The sum of the thinking and breaking distances.
Thinking Distance
The distance a vehicle travels during the drivers reaction time. This can be affected by tiredness, drugs or alcohol.
Vector Quantities
Quantities that have a magnitude and a direction.
Represented by an arrow, length for magnitude and direction of arrowhead for direction.
Velocity-Time Graph
A plot of how an objects velocity changes over time.
Gradient of a Velocity-Time Graph…
Acceleration
Area Underneath Velocity-Time Graph
The objects displacement
Velocity
A measure of the rate of change of displacement.
Scalar Quantity
Weight
The force acting on an object due to gravity.
Weight is Equal to…
Mass*Gravitational Field Strength
