physics p4 Flashcards
which of these following distances will be affected if a driver is under the influence of alcohol ; thinking distance , breaking distance , stopping distance=
thinking distance and stopping distance
what is a vector quantity
a vector quantity has both magnitude (size) and direction
what are the units of speed distance and time
speed = M/S distance = M time= s
how is the weight of a object calculated
weight = mass x gravitational field strength
what is displacement
distance from the starting point in a straight line in a particular direction . it is a vector quantity
what type of quantity is momentum (explain)
momentum is a vector quantity because it has both direction and magnitude
define breaking distance
the distance the vehicle travels before the vehicle stops once the breaks have been applied
what is the vector equivalent of A)speed B) distance
A) velocity B) displacement
which equipment is used to measure speed and acceleration
light gates and datalogger
which equipment is used to measure time
a stop watch
what is a scaler quantity
a scalar quantity has only magnitude and no direction
if you run two full laps of 400m athletics track what is your A) distance B) displacement
A) distance = 400 x 2 = 800m
B) displacement = 0 as you are at starting point
when a object experiences a force its momentum ______
changes
in a crash the drivers momentum goes from high momentum to ____ momentum very quickly the longer the time taken to stop the _______ the force on the driver and the smaller the risk of injury . air bags seatbelts and crumple zones all ______ the amount of time it takes the driver to stop moving during a collision
zero
smaller
increase
a book rests on a table the force acting on the book are its weight (due to gravity) and the normal reaction force due to contact with the table are these two forces an interaction pair
and explain
no they are not an interaction pair because they are not the same type of force and they both act on the same object (the book)
write down 3 safety features that is in a car to protect you
air bags , seatbelts, crumple zone
complete newtons third law of motion ; if object A exerts a force on object B , object B will exert a force on object A that is:
equal in magnitude , opposite in direction , and off the same type
what is acceleration and how is it calculated? give both the definition and equation
acceleration is the rate of change of velocity
acceleration = (final velocity - initial velocity ) / time taken
rearrange the speed equation to make distance the subject and make time the subject
distance = speed x time
time = distance / speed
complete the equation of thinking distance
thinking distance = speed of the vehicle x drivers reaction time
what is the equation for vehicle stopping distance
stopping distance = thinking distance + breaking distance
what is the magnitude of gravitational field strength on earth with units
G= 10N/KG
state the equation linking change of momentum and a force
change of momentum = force x time
what is velocity? give definition and the equation
velocity is the rate of change of displacement . it is the speed in a given direction
calculation :
velocity = displacement / time
vector quantity
how is speed calculated
speed = distance / time
the faster your reactions the __________ your reaction time
shorter
what is the name of the force that acts at right angles to an object resting on a surface
normal reaction force
3 factors that could increase human reaction time
drinking alcohol , distractions , being tired
what is the equation for momentum
momentum = mass x velocity
write down three factors affecting car breaking distance
condition of the tires , condition of the road , condition of the breaks
during a collision momentum is conserved what does this mean
total momentum before collision = total momentum after collision
define thinking distance
the distance the vehicle travels during the drivers reaction time when they have seen a hazard
