FWAQ Flashcards
What is meant by the term half life
The time taken for the half the radioactivity to decay
Explain the stage of a falling object
Object is accelerating
downward force is greeter than upward force
Forces are unbalanced
There is resultant force
As the upward force increases so does the downward force
Resultant force decreases
forces become balanced
resultant force is to equal to zero
terminal velocity is achieved
Describe the relationship between temperature and resistance ( reference to graph)
As temperature increases the resistance of the thermistor decreases
current increases
non- linear graph
what are the conditions for nuclear fusion to occur in a core star
Very high temperature
Very high pressures
very high kinetic energy
to overcome electrostatic repulsion
what is the human hearing range
20-20000 Hz
What are advantages and disadvantages of hydroelectricity
Advantage
- doesn’t take up too much land
- not weather dependant
Disadvantage
- can cause floods in large areas
- Expensive to build
requires a large dam
- installation is permanent
Describe the energy transfer that are involved in generating electricity in a hydroelectric power station
Reduction in GPE store of water
mechanical work done on turbine
increase in KE store of turbine
mechanical work done on generator
increase in KE store of generator
Mechanical work done on generator
Increase in KE store of generator
Idea of electrical work done on grid
Explain how red- shift galaxies supports the big bang theory
The further the galaxy is from earth the greater the red shift
The greater the red-shift, the faster the galaxy is moving away
Speed of the galaxies increases with increased distance
The speed and distance are directly proportional
Relationship between speed and distance implies expansion
expansion implies there was a single point in the past
