Physics Paper 2 GCSE Flashcards
What does scalar quantities only have?
magnitude
What does vector quantities have?
magnitude and an associated direction
How is vector quantities represented?
arrow
What does the length of the vector quantities arrows show?
magnitude
What does the direction of the arrow representing vector quantities show?
direction of the vector quantity
What is a force?
a push or a pull that acts on an object due to the interaction with another object
What are the forces between objects?
contact forces - the objects are physically touching
non-contact forces - the objects are physically seperated
What is weight?
force acting on an object due to gravity
What does the weight of an object depend on?
gravitational field strength at the point where the object is
How do you calculate weight?
mass x gravitational field strength
What is the gravitational field strength of the earth?
10 n/kg
How do you calculate work done?
force x distance
What is one joule in newton-metre?
1 newton-metre
What does work done against the frictional forces acting on an object cause?
rise in the temperature of the object.
To change the shape of an object what must happen?
more than one force has to be applied – this is limited to stationary objects only
Whats elastic deformation?
elastic deformation is a change in shape of a material at low stress that is recoverable after the stress is removed.
Whats inelastic deformation?
a deformation occurring when a material is stressed beyond its elastic limit.
What is the extension of an elastic object like compared to the force applied?
The extension of an elastic object, such as a spring, is directly proportional to the force applied, provided that the limit of proportionality is not exceeded.
How do you calculate force?
spring constant x extension
What type of energy is stored in a spring?
elastic potential energy
How do you calculate elastic potential energy?
0.5 x spring constant x (extension)2
How do you calculate moment of a force?
force x distance
How can you calculate pressure?
force normal to a surface/area of that surface
height of the column x density of the liquid x gravitational field strength
A partially (or totally) submerged object experiences what?
a greater pressure on the bottom surface than on the top surface. This creates a resultant force upwards. This force is called the upthrust.
What does displacement include?
Displacement includes both the distance an object moves, measured in a straight line from the start point to the finish point and the direction of that straight line. Displacement is a vector quantity.
What is speed?
Speed does not involve direction. Speed is a scalar quantity
What is a typical value of someone walking?
1.5 m/s
What is a typical value of someone running?
3 m/s
What is a typical value of someone cycling?
6 m/s
What is the typical value for the speed of sound in air?
330 m/s
For an object moving at constant speed the distance travelled in a specific time can be calculated using what equation?
speed× time
What is the velocity?
The velocity of an object is its speed in a given direction. Velocity is a vector quantity.
Motion in a circle involves what?
constant speed but changing velocity.
How do you calculate acceleration?
change in velocity/time taken
The distance travelled by an object can be calculated using what?
the area under a velocity–time graph
How do you calculate uniform acceleration?
(finalvelocity)2− (initialvelocity)2 = 2 x acceleration× distance
Near the Earth’s surface any object falling freely under gravity has an acceleration of what?
9.8 m/s2
An object falling through a fluid initially accelerates due to what?
force of gravity. Eventually the resultant force will be zero and the object will move at its terminal velocity.
What is newtons first law tell us?
If the resultant force acting on an object is zero and:
• the object is stationary, the object remains stationary
• the object is moving, the object continues to move at the same speed and in the same direction. So the object continues to move at the same velocity. So, when a vehicle travels at a steady speed the resistive forces balance the driving force. So, the velocity (speed and/or direction) of an object will only change if a resultant force is acting on the object.
What is Newtons second law?
The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.
resultant force = mass x acceleration
• inertial mass is a measure of how difficult it is to change the velocity of an object
• inertial mass is defined as the ratio of force over acceleration.
What is newtons third law?
Whenever two objects interact, the forces they exert on each other are equal and opposite.
What is stopping distance of a vehicew?
the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance).
What is the reaction time of a person?
Typical values range from 0.2 s to 0.9 s.
How do you calculate momentum?
mass x velocity
What are the two types of waves?
transverse or longitudinal
The ripples on a water surface are an example of what?
transverse waves
What are sound waves?
longitudinal wave
what does Longitudinal waves show?
areas of compression and rarefaction
What is an amplitude of a wave?
maximum displacement of a point on a wave away from its undisturbed position.
What is the wavelength of a wave?
distance from a point on one wave to the equivalent point on the adjacent wave
What is the frequency of a wave?
number of waves passing a point each second.
How do u calculate the period?
1/frequency
What is wave speed?
speed at which the energy is transferred (or the wave moves) through the medium.
How do you calculate wave speed?
frequency x wavelength
What does sound waves withing the ear cause?
cause the ear drum and other parts to vibrate which causes the sensation of sound. The conversion of sound waves to vibrations of solids works over a limited frequency range. This restricts the limits of human hearing.
What is the range of normal human hearing?
20Hz to 20kHz
What are electromagnetic waves?
transverse waves that transfer energy from the source of the waves to an absorber. Electromagnetic waves form a continuous spectrum and all types of electromagnetic wave travel at the same velocity through a vacuum (space) or air.
Types of waves from long wavelength to short wavelength or low frequency to high frequency?
Radio waves microwaves infrared visible light ultraviolet X-rays Gamma rays
Different substances may what?
Different substances may absorb, transmit, refract or reflect electromagnetic waves in ways that vary with wavelength
Radio waves can be produced by what?
oscillations in electrical circuits.
When radio waves are absorbed they may create a what?
alternating current with the same frequency as the radio wave itself, so radio waves can themselves induce oscillations in an electrical circuit.
Changes in atoms and the nuclei of atoms can result in what?
electromagnetic waves being generated or absorbed over a wide frequency range. Gamma rays originate from changes in the nucleus of an atom.
Ultraviolet waves can cause what?
skin to age prematurely and increase the risk of skin cancer.
What type of radiation is X-rays and gamma rays and what does it cause?
ionising radiation that can cause the mutation of genes and cancer.
How do u calculate magnification?
image height/object height
all bodies (objects) emit what?
radiation
the intensity and wavelength distribution of any emission depends on what?
the temperature of the body
A body at constant temperature is absorbing radiation at the same rate as it is what?
emitting radiation. The temperature of a body increases when the body absorbs radiation faster than it emits radiation.
The temperature of the Earth depends on many factors including what?
the rates of absorption and emission of radiation, reflection of radiation into space.
the temperature of a body is related to what?
the balance between incoming radiation absorbed and radiation emitted
The poles of a magnet are the places where the magnetic forces are what?
stringest
A permanent magnet produces its own what?
magnetic field.
An induced magnet is what?
a material that becomes a magnet when it is placed in a magnetic field. Induced magnetism always causes a force of attraction. When removed from the magnetic field an induced magnet loses most/all of its magnetism quickly.
A magnetic compass contains what?
a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field.
When a current flows through a conducting wire a magnetic field is produced around the wire. The strength of the magnetic field depends on what?
the current through the wire and the distance from the wire.
Shaping a wire to form a solenoid increases what?
the strength of the magnetic field created by a current through the wire.
How do you calculate force which included magnetic flux density?
magnetic flux density x current x length
What is the basis of an electric motor?
A coil of wire carrying a current in a magnetic field tends to rotate
