Topic 5 - Forces Flashcards
What are the two types of forces
forces are either push or a pull on an object by interacting with something.
What is a contact force and examples
two objects have to be touching for a force to act. e.g. friction, air resistance.
What is a non-contact force and examples
the objects do not need to be touching for a force to act. magnetic force, gravitational force.
what is an interaction pair of forces
it is a pair of forces that are equal and opposite and act on two interacting objects.
what is gravitational force
it is the force of attraction between masses
what is mass
mass is just the amount of stuff in an object
what is weight
weight is the force acting on an object due to gravity and gravitational field
what is the difference between mass and weight
mass is just the amount of stuff, same anywhere in the universe. weight will change depending where it is in the universe due to the gravitational field strength
weight equation
weight (N) = Mass (Kg) X Gravitational field strength (N/Kg)
what is resultant force
it is the overall force on a point or object.
how can replace forces to make a single, resultant force
you can replace the number of forces acting on a object with a single (so long as it has the same effect as the other forces) this is called resultant force.
how is work done with resultant force
when a force moves an object through a distance, energy is transferred and work is done on the object.
how to find out how much work is done with a resultant force
Word done (J) = Force (N) X Distance (M)
how does a object stretch, compress or bend
by applying a force it can do one of those three. to do this you need more than one force acting on an object.. it does this with work done.
what is a elastically deformed shape
it can go back to its shape after the force has been removed
what is an inelastically deformed shape
it doesn’t return to its original shape when the forces has been removed
what is the extension of a spring
the extension of a spring is directly proportional to the load or force applied
equation for extension
Force (N) = Spring constant (N/m) X Extension (m)
what happens when the force is too great for the spring
when the force is too great the springs limit of proportionality is reached and the spring will not return to its original shape.
what are vectors
force is a vectors quantity - they have a magnitude and a direction.
examples of vector quantities
force, velocity, acceleration
