forces (paper 2) Flashcards
define a vector quantity
physical quantity that has magnitude and direction
define a scalar quantity
physical quantity that has magnitude but no direction
list 5 vector quantities
force
velocity
displacement
acceleration
momentum
list 5 scalar quantities
speed
distance
mass
temperature
time
define a force
a push or pull on an object that is caused by it interacting with something
forces can change an objects? What?
shape
motion
define contact forces
where the two objects must touch each other
define non contact forces
where the objects dont need to touch
what is the resultant force
single force that has the same effect as all the forces acting on an object
what is the moment of a force?
a measure of the turning effect of the force on an object
define the centre of mass
the point which its mass can be thought of as being concentrated
what happens when an object is freely suspended
it comes to rest with its centre of mass directly underneath the point of suspension
what effect does a low gear give?
low speed high turning force
what effect does a high gear give
high speed low turning effect
what velocity does an object have at rest
zero
define acceleration
the rate of change of velocity
what is the resultant force
single force that has the same effect as all the forces acting on an object
define mass
quantity of matter in an object
define weight
force acting on an object due to gravity
define the terminal velocity of an object
when an object reaches a constant velocity due to its weight being equal to the frictional forces on it
give 3 thinking distance examples
alcohol/drugs
mobile phone
tiredness
give 3 braking distance examples
worn brakes
worn tyres
icy road
give 1 stopping distance example
speed
v=?
final velocity
u=?
initial velocity
a=?
acceleration
s=?
distance travelled
how can you tell if an objects elastic?
returns to its original shape when the forces deforming it are removed
what does Hookes law state?
extension of a spring is directly proportional to the force applied as long as its limit of proportionality is not exceeded
how many joules 0f work does 1 Nm equal
1 joule
