physics

Created by

Maeve

Cards (51)

what is nuclear fission
the splitting of large unstable nuclei to form more stable nuclei
what needs to happen so nuclear fission can take place
and unstable nuclei must absorb a nutron
what is fissile nuclei 
where fission can happen through the absorption of slow neutrons
what is emitted in a fission reaction
neutrons
gamma rays
energy
what form of energy do all fission products have
kinetic energy
name a fissile nuclei
uranium-235
what are the three main components in a nuclear reactor
fuel rods
control rods
moderator
What is a chain reaction? 
when each fission event causes further fission events.
what is a uncontrolled chain reaction and what are the consequences
where rate of fission is high and too much energy is being produced
may cause a nuclear explosion
how can you control a chain reaction in nuclear fission
-control rods and placed in-between fuel rods
the rods control rate of fission by moving them up or down
the control rods absorb the neutrons
how can control rods reduce rate of fission
the lower the rods the lower the rate of fission
moderater slows down the speed of the nuclei
what does a moderator do
slows down the speed of the nuclei reducing rate of fission
What is nuclear fusion?
the joining of two light nuclei to produce a heavier nucleus and release energy
what releases more energy nuclear fission or fusion
fusion
disadvantages of nuclear fusion
-requires high temperature and high pressure
-difficult to contain
what must the casing of a fission reactor do
the neutrons collide with the wall of the container and produce gamma waves
to prevent this they need concrete to absorb the gamma radiation to prevent it from passing through to the outside reactor
positives to nuclear fission
no pollution
1kg of nuclear elements make more energy than 2kg of coal
large supply
negatives of nuclear fission
produces radioactive waste
not an infinite source
could exploid
could be targeted by terrorists
positives to nuclear fusion
infinite resorce
produces more energy than fission
in a distance time graph what does a a straight horizontal line represent
a stationary object
in a distance time graph steeper line represents...
a faster contant speed
in a distance time graph what does a straight diagonal line represent
constant speed
in a speed time graph what does a straight diagonal line represent
constant acceleration
in a speed time graph what does a diagonal line represent
a greater constant acceleration
in a speed time graph what does a straight horizontal line represent
a constant speed
how do you work out distance traveled in a speed time graph
area under the line
what makes up stopping distance
Thinking distance + braking distance
the effects on braking distance
wet/icy weather conditions
road surface
steepness of road
speed of car.
the effects on thinking distance
alcohol
drugs
tiredness
mobile phone
speed of car
is speed increases what happens to stopping distance
stopping distance increases
What is inertia? 
inertia is the resistance of an object to change what its doing
newtons first law 
any object will continue In its state of rest or move with constant velocity unless acted upon by an external resultant force
vector 
A quantity that has magnitude and direction
Scalar 
a quantity that has only magnitude (size)
examples of scalar quantities 
speed, distance
examples of vector quantities
displacement, velocity
newtons second law of motion
the resultant force is mass times acceleration
newtons third law 
if an object A exerts a force on object b then object b will exert an equal but opposite force on object A
what is terminal speed
1) The force of resistance equals the gravitational pull on the object

2) The object doesn't accelerate

3) It falls at a constant speed
what's the difference between weight and mass
Weight depends on gravity and mass is constant