Physics P2 Flashcards
(17 cards)
What is meant be elastically deformed? (2)
-It will return to its original shape
-When the force is removed
Explain why a star is stable in its main sequence stage (2)
-gravitational force inwards and forces as a result of fusion reactions outwards
-are in equilibrium / balanced
Describe what will happen to a star (The same size as our sun) between the main sequence stage and the end of a stars life cycle (3)
-(the star will) expand to become
a red giant
-(the star will) collapse to
become a white dwarf
-(the star will) cool to become a
black dwarf
Describe the difference between transverse and longitudinal waves (2)
in a transverse wave, the
oscillations are perpendicular to the direction of energy transfer
in a longitudinal wave, the
oscillations are parallel to the direction of
energy transfer
What is the advantage of repeating measurements 3 times and calculating a mean? (1)
To reduce the effect of random errors
Describe how the force on a pedal causes a moment in a rear axle (2)
the force on the pedal causes a moment about the pedal axle
which causes a force on the chain which causes a moment about the rear axle
Explain how a moving coil loudspeaker produces a sound wave (4)
-current creates a magnetic field
around the coil
-which interacts with the
permanent magnet field
-producing a resultant force
causing the coil to move
-when the direction of the
current reverses, the direction of
the resultant force reverses
producing a sound wave
Explain how Fleming’s left hand rule can be used to predict the direction in which … will move (5)
-hold thumb first finger and second finger of left hand at right angles to each other
-second finger represents the current pointing out of the paper
-first finger represents the field pointing (insert direction here)
-thumb points in the direction of the force
-(therefore) the rod moves (insert direction here)
Give 2 factors that increase the braking distance of the car
-Icy road conditions
-Poor tyre conditions
Explain why the driver’s reaction time affects the thinking distance of a car (2)
-Distance = speed x time
-Longer reaction time = longer distance
Explain why the average speed of a car between speed cameras and the average velocity of the car between cameras are different (3)
-Speed is a scalar but velocity is a vector
-The road is not straight
-Therefore the direction changes so velocity changes
Why does hailstone accelerate?
-There is a resultant force acting
-(Force from gravity is greater than the force from air resitance)
Explain why a hailstone reaches terminal velocity (3)
-As the hailstone accelerates the air resistance increases
-Eventually air resistance becomes equal to the weight of the hailstone
-So the RESULTANT FORCE is 0
What is the unit for mass?
Kg
Explain how there is evidence for the big bang (2)
-Furthest galaxies are moving away from the milky way the fastest
-Suggesting all matter started at the same point
Explain why there is an alternating current in the output when the transformer is connected to a circuit (3)
-Alternating current causes a magnetic field around the primary coil
-This creates an alternating magnetic field in the core
-This induces an alternating potential difference in the secondary coil which causes an alternating current
Explain why the forces on the brick at the bottom of the swimming pool cause the brick to be stationary (3)
-Upthrust acts upwards on the brick
-Normal contact force acts upwards on the brick
-Weight is equal to upthrust and the normal contact force
