Forces Flashcards
Vector and scalar properties
Vector -magnitude and direction
Force ,velocity,displacement
Scalar -magnitude only
Speed ,distance, temp
Definition of reselutatnt force
When a force moves an object through a distance ,energy is transferred and work is done on the object
What elastic and inelstic deformation
Electrically deformed object will go back to its original shape and force is removed
In elastic deformation the object dosnt change back it’s original shape after force is removed
What is the realtionship between force and extension
They’re directly proportional and when the graph curves this is the Called the point of proportionality
Typical everyday speed
Walking-1.5m/s
Running-3m/s
Cycling-6m/s
Car-25m/s
Train-55m/s
Plane -250m/s
What does shape of distance graph show you
Gradient=speed
Flat sections are object as stopped
Stright uphill means steady speed
Curves mean acceleration of deceleration
Levelling off curve means slowing down
Steepening curve means object is speeding up
You can find speed at point though tangent
What does velocity graphs show
Gradient= acceleration
Flat sections means steady speed
Steeper the graph the greater acceleration or decceleration
Positive stright lines are constant acceleration negative stright lines are constant deceleration
Properties of drag
Drag is a resistance you get in a fluid
Air resistance is a type of drag
Drag increases as speed increases
Procces of terminal velocity
When objects first fall force of gravity is much more than frictional force so it accelerates
As speed increases friction builds up
Friction reduces the acceleration UNTILL frictional force is equal to accelerating force so resultant force is zero
It will have reached terminal velocity and fall at steady speed
What does terminal velocity depend upon
Objects with larger surface area have lower terminal velocity’s
Due to them having more air resistance so it spents less time accelerating
Newtons first law
If the resolutely force on a stationary object is zero the object will remain stationary
If the resolutely force on an object is zero it will carry on moving in the same velocity
Newton’s second law
Resolutely force= mass x acceleration
What inertia and Newton’s third law
Inertia is the tendency for a motion to stay unchanged
When two objects interact the forces they exert on each other are equal and opposite
Properties of stopping and thinking distances
Stopping distance=thinking distance+breaking distacne
Thinking distacne is affected by
Your speed
Your reaction time
Breaking distance is affected by
Your speed
Weather or road service
Condition of tires
How good your brakes are
The procces of breaking
Break pedal pushed ,break pads pressed on wheels this causes friction which caused work to be done
The work done transfers energy from the kinetic energy store of the wheels to the thermal energy of breaks
