P2 - Exam Mistakes Flashcards
What are the 4 advantages of nuclear fusion compared to nuclear fission in generating electricity?
Increases supply of electricity
Less environmental damage
Makes another source of energy available
Able to meet global demand
What is nuclear fission?
The splitting of a NUCLEUS
How do you calculate the maximum speed of an object when the the distance / time graph is a curve?
Work out the gradient where the gradient is steepest
What by the statement momentum is conserved?
Momentum before = momentum after
Why do seat belts make a driver safer in a car crash? 4 marks
The seat belt stretches
So the driver travels a greater distance while slowing down and stopping (than a driver hitting a hard surface)
For the same amount of work done,
A smaller force is exerted on the driver so they are less likely to have serious injury than someone without a seatbelt
Explain in terms of electrons and ions inside the filament, why resistance increases with temperature in filament lamps? 2 marks
Ions vibrate faster
Electrons collide more frequently with the ions
How does the velocity of an air-powered rocket change as the rocket moves upwards and why?
The velocity decreases until zero
Because the resultant force (air resistance and weight) acts in opposite direction to motion
What is the difference between velocity and speed?
Velocity includes direction because it is a vector and speed is a scalar
What pattern links the angle at which the air powered rocket is launched and the range of the rocket? 2 marks
Range increases up to 45 degrees
Range decreases from 45 degrees
A child goes down a slide. The child becomes electrically charged when he goes down the slide. Why? 2 marks
There is friction between the child and the slide
This causes electrons to transfer between child and slide
Why did going down the slide cause the child’s hair to stand on end? 2 marks
All of the charges on the hair are the same
Like charges repel meaning that the hairs repel each other
Why would the child not become charged if the slide was metal?
Metal is a conductor meaning the charge could through the metal to earth
What would a temperature / resistance graph look like for a thermistor?
Resistance on Y axis
Temperature in X
Starts by rapidly decreasing
Rate of decrease gradually slows
Why is it important that ammeters have a low resistance?
So that ammeter affects current as little as possible
A boat is pulling on a water skier. The force on the water by the propeller is backwards. Why does this force cause the boat to move? 2 marks
Produces a force from the water onto the boat
In the forward direction
