P2 Forces Flashcards
Does a scalar quantity have magnitude and direction or just magnitude?
just magnitude
Are forces scalar or vector quantities?
vector
What is a contact and a non-contact force?
Contact - force that occurs between objects that are physically touching
non-contact - force that occurs without the objects touching each other
Name some contact forces.
friction, drag, tension, normal, upthrust
Name three non-contact forces.
gravity, electrostatic, magnetism
What is gravity?
Force of attraction between all masses
What is mass?
The amount of matter that an object is made up of and is constant in all areas of the universe
What is weight?
The force acting due to gravity and is dependent of the gravitational field strength of that planet.
What is the centre of mass?
The weight of an object acting at a single point
What is the equation linking weight, mass, and gravitational field strength
W=mg
What do the length of the arrows in a free body diagram represent?
The magnitude of the force
What is a free body diagram used for?
To show the different forces acting on an object
How are vectors added in a scale vector diagram?
Head to tail
Define work done
The force on an object over a particular distance
What does 1 joule of work done mean for the amount of displacement.
1 joule = 1 newton metre
What also takes place during work done?
energy transfers
What does it mean if an object is elastically deformed?
It can return back to its original shape once the force is removed.
What does it mean if an object is inelastically deformed?
It cannot return back to its original shape once force is removed
Describe the relationship between extension and force
They’re directly proportional
What happens to the relationship once the limit of proportionality is exeeded?
It is no longer linear
What does the gradient on a force-extension graph represent?
The spring constant
What is the spring constant?
It refers to how easy it is to stretch or compress a spring
What type of energy is stored if any force is applied to a spring?
Elastic potential energy
What is the relationship between work done and the energy stored?
They are equal if the limit of proportionality is not exceeded
What is a moment?
The rotational force around a pivot
What are the moments equal to in a balanced object?
total clockwise moment = total anticlockwise moment
What are the purposes of levers and gears?
- transmit rotational effects of forces
- magnify the size of an applied force or the distancec a force moves over
