Forces Flashcards
what is a vector
a quantity that has magnitude and direction
what is a scalar
a quantity that only has magnitude
give examples of scalars
temperature
mass
energy
speed
density
distance
give examples of vectors
force
weight
displacement
velocity
acceleration
momentum
what is a contact force
when the objects are touching
what is a non contact force
the objects are not touching
give examples of contact forces
friction
air resistance
tension
normal contact force
upthrust
give examples of non contact forces
gravitational force
electrostatic force
magnetic force
what is gravity
the force of attraction between all masses
what is the equation for weight
mass x gravitational field strength
what is the resultant force
A number of forces acting on an object may be replaced by a single force that has the same effect as all the original forces acting
together
what must be done to change the shape of an object
more than one force must be applied
what does elastically deformed mean
if the object returns to its original shape after the forces are removed
what does inelastically deformed mean
if the object does not return to its original form
what is the equation for force
spring constant x extension
elastic potential energy equation
0.5 x spring constant x extension squared
what is distance
how far an object moves (scalar quantity)
what is displacement
includes the distance the object has moved and the direction
what is velocity
the speed of an object in a given direction
what will the line look like on a distance time graph is the object is accelarating
the line will be curved
what is the equation for acceleration
change in velocity / time taken
what is newtons first law
the object will remain in the same state of motion unless acted upon by an external force
what is inertia
the tendency of objects to continue in their state of rest
what is newtons second law
The acceleration of an object is proportional to the resultant force
acting on the object, and inversely proportional to the mass of the
object
what is the equation for force
mass x acceleration
what is newtons third law
every action there is an equal opposite reaction
what is the stopping distance
the sum of the distance the vehicle travels during the drivers reaction time
what does the stopping distance depend on
thinking distance - distance travelled during the drivers reaction time
braking distance - distance travelled under the braking force
what is the conservation of momentum
In a closed system, the total momentum before an event is equal to the total momentum after the event.
