2019 Paper 2 Flashcards
Describe how apparatus for standing wave practical could be adjusted to show one complete wave without changing frequency
Move the wooden bridge to the right
Add more mass to the string
How could someone investigate how the speed of a wave on a stretched string depends on the tension of the string
Add more mass to the string
Adjust frequency using signal generator and wooden block
Observe standing wave
Measure wavelength of it
Calculate wave speed from frequency and wavelength
What do you need to make sure you do when drawing a solenoid
Work out which way is North Pole and add appropriate arrows (north points outward)
Explain why when two iron rods are placed in a solenoid they move apart
Rods become induced magnets with the same polarity at each end
What does increased speed do to stopping distance
Increases it as increased speed increases Kinetic energy so increases work done to stop vehicle
(Also more mass)
Give a reason why someone’s results for a experiment could be not valid
They changed two independent variables at the same time so it’s not possible to know the effect of one variable or the other
Give a reason why someone’s results for a experiment could be not valid
They changed two independent variables at the same time so it’s not possible to know the effect of one variable or the other
How does Big Bang theory state universe began
From a extremely hot and dense point
A galaxy called “A” is moving torwards the earth. Describe how the wavelength and frequency of light from galaxy A seem to have changed when viewed from earth
Wavelength seems to have decreased
Frequency seems to have decreased
Explain why an egg is less likely to break when dropped onto soft foam rather than a concrete floor
Soft foam increased the time taken for egg to stop which decreases rate of change of momentum and reduces force on the egg
Explain how properties of x rays make them suitable for medical imaging of bones
X rays pass through SOFT tissue but are absorbed by bone
Explain the changing motion of a skydiver
Initially accelerates due to the fact that weight is more than air resistance. Acceleration causes air resistance to increase which causes air resistance to become equal to weight so sky diver falls at terminal velocity
Why does increasing the distance you jump from as a sky diver increase speed
The higher altitude means less dense and
So air resistance on the sky diver falling at 39000 was less than someone jumping at 4000
So sky diver was able to accelerate longer before reaching terminal velocity
What’s the function of a microphone
To convert sound waves into variation in current
Describe how a microphone works
Uses generator effect
Sound waves cause diaphragm to move wich causes the coil to VIBRATE. The coil therefore cuts magnetic field lines. A potential difference is induced. If curcuit is complete a current is also induced
