P2.2 -Forces Flashcards
what happens in an interaction pair (N3)?
- forces act in opposite directions
- each force is the same magnitude
what is newton’s third law?
“when two bodies interact, they exert a force upon each other that is equal in size, but opposite in direction”
state three non-contact forces?
- gravity
- electrostatics
- magnetism
how does gravity interact with objects?
attracts them
how do electric charges interact with objects?
- attract and repel
what is a field of a force?
the region where an electric charge, a magnetic material or a mass experiences a force
how are forces represented?
with a force arrow
where does a force arrow start on an object for a non-contact force?
the centre
where do you draw contact force arrows from?
the point of contact
use what you know about the structure of the atom to suggest why a non-contact force is produced within an atom
- there are electrons on the outsides of atoms.
- As you push them together they repel.
- This is an electrostatic force, which is a non-contact force.
what is terminal velocity?
the velocity at which a body falls through a medium, when the drag acting on the body is equal to its weight
what planes do we consider when explaining the motion of an object at an angle?
- the plane perpendicular to the slope
- the plane parallel to the slope
what is air resistance?
when an object moves through air and collides with other air molecules
what is tension?
the pulling force that a string or cable exerts when something or someone pulls in it
what is friction?
- when two surfaces are touching and try to move against each other.
how does friction work?
- Tiny bumps in the surface interlock (overlap or fit together). This creates a frictional force that opposes their motion.
what kind of force is air resistance?
contact (air particles collide)
what does a free body diagram show?
shows the forces acting on a single object
what is a resultant force?
the force when two or more forces are added together
what is a force?
a push of a pull
an attraction or repulsion
what can a force do?
- change the shape of an object
- change the motion of an object
what are forces measured in?
N (newtons)
state one way in which the force of gravity is different to the electrostatic force
- gravity can only attract
- electrostatic force can attract and repel
what happens when bodies interact?
- exert forces upon each other
what does a free body diagram show?
all the forces acting on a single body
what does it mean to resolve a force?
- work out how much of it acts in the horizontal plane
- work out how much of it acts in the vertical plane
what is Newton’s First Law?
“A body will remain at rest, or continue to move at a uniform velocity, unless acted upon by a resultant force”.
what is Inertia?
A measure of how difficult it is to change the velocity of a body (either from rest or when traveling at a uniform velocity)