basic knowledge Flashcards
what is a contact force
a contact force is any force that occurs as a result of two objects making contact with each other
what is a non-contact force
A non-contact force is a force which acts on an object without coming physically in contact with it.
what is a force
A force is a push or pull that acts on an object due to the interaction with another object.
give 4 examples of a contact force
normal contact force, tension, air resistance and friction
name 3 non-contact forces
gravitational force, electrostatic force and magnetic force
what is a force measured in
newtons (N)
motion is caused by what?
forces
a physical quantity can be what?
measured
what are the two types of quantity
scalar and vector
magnitude is what?
the amount of a quantity eg height size or brightness
what is a scalar quantity
a quantity with only magnitude and lacking in direction
what is a vector quantity
a quantity with both magnitude AND direction
which quantity has both magnitude AND direction
vector
vector quantities are represented using a what?
an arrow
The length of the arrow shows the ____
magnitude
what is tension?
tension is a pulling force exerted on an object by a string, rope or rod
Tension is a pulling force exerted on an object by a ____, ____ or ____
string, rope or rod
what is friction?
friction is a force that acts between two touching surfaces and prevents or resists them moving against each other.
when does an object experience air resistance?
when an object moves through the air it experiences air resistance. This force acts against the direction of movement.
the more ____ an object is moving, the more air resistance it will experience
quickly
what is upthrust?
Upthrust is an upwards force that acts on an object when it is in a fluid
what is thrust?
Thrust is a driving force exerted by an engine to make an object move.
what is a normal reaction force?
When an object pushes on a surface like a table, wall or the ground, the surface pushes back on the object with a balancing force.
the normal reaction force always acts at ______ to the surface.
right angles
when can friction be useful?
brakes on a bike
when can friction be a nuisance
In the moving parts of the chain and gears of a bike
what is magnetism?
attraction or repulsion that arises between electrically charged particles because of their motion
what is an electrostatic force?
Electrostatic force is experienced by a charged particle in an electric field.This force can be either attractive or repulsive.
what is gravitational force?
Gravitational force is experienced by a mass when it is sufficiently close to another mass.
what force only ‘pulls’
gravitational force
what 7 effects can a force have on an object?
make a body that is stationary to move
make a body that is moving to become stationary
decelerate the speed of a moving body
accelerate the speed of a moving body
change the direction of a moving body
change the shape of a moving body
change the size of a moving body
what are forces measured by?
a newton meter
what must be done to a newton metre before it’s used and why?
it must be set to 0 because otherwise a systematic error would occur and all your measurements will be inaccurate by the same amount
