s3 phy Flashcards
define a physical quantity
a physical quantity is a quantity that can be measured. It consists of a numerical magnitude and a unit.
how long is a period of a pendulum
the time taken for one complete oscillation
how long is one complete oscillation
each complete to-and-fro motion
what is a scalar quantity
physical quantities that only have magnitude
what is a vector quantity
physical quantities that have both magnitude and direction
name 5 examples of scalar quantities
distance, speed, mass, energy, time
name 5 examples of vector quantities
displacement, velocity, acceleration, force, weight
define speed
speed is the distance moved per unit time
speed formula
distance/time
define velocity
velocity is the rate of change of displacement
formula of velocity
displacement/time taken
how do we calculate average speed?
total dist travelled/total time taken
how do we calculate the average velocity
total displacement/total time taken
define acceleration
acceleration is the rate of change of velocity
how do we calculate acceleration
change of velocity/time taken
define uniform acceleration
the constant rate of change of velocity
how can we calculate uniform acceleration
change in velocity/change in time
what does the gradient of a distance-time graph show
the speed of an object
what does the gradient of a speed-time graph show
the acceleration of the object
how can you calculate the distance of an object
the area under the speed-time graph
define mass
mass is a measure of the amount of matter in a body
define weight
the gravitational force acting on an object that has mass
what is a gravitational field
a gravitational field is a region in which a mass experiences a force due to gravitational attraction
define gravitational field strength
the gravitational force per unit mass placed at that point
how do we calculate gravitational field strength
g = weight/mass of the object
if an object were to free fall under gravity without air resistance, we ca find its acceleration using the equation
F(resultant force) = mass times acceleration
define density
mass per unit volume
calculate density
p(density) = mass/volume
define pressure
the force acting per unit area
calculate pressure
P(pressure) = F(force)/A(contact area)
what is Newtons first law of motion?
that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.
what is Newtons second law of motion?
that when a resultant force acts on an object of a constant mass, the object will accelerate in the direction of the resultant force.
how do we calculate resultant force?
F=ma
what is Newtons third law of motion?
that if body A exerts a force F on body B, then body B will exert an equal and opposite force F on body A (e.g: a swimmer pushing hit feet against the wall of the pool)
define friction
friction is the contact force that opposes or tends to oppose motion between surfaces in contact.
how do we calculate moments?
M = F (force applied (N)) x d (perpendicular distance from pivot to the line of action of the force (m))
what is the principle of moments?
that when a body is at a equilibrium (balanced), the sum of clockwise moments about a pivot is equal to the sum of anticlockwise moments about the same pivot.
define centre of gravity of an object
an imaginary point where the entire weight of the object seems to act.
what is the si unit for energy?
joule ( J )
how do we calculate the size of a kinetic energy store of a body moving at speed v
KE = 1/2 mv^2 m=mass(kg), v=speed(m/s)
how do we calculate the amount of energy in the gravitational potential store of a body at hight h above the ground?
GPE = mgh m=mass(kg), g=gravitational field strength (N/kg), h=height(m)
what is the principles of conversion energy?
that energy cannot be created or destroyed, can be transferred from one store to another, the total energy of an isolated system is constant.
how can we calculate work done?
work done = f(N) x d(m)
what is the kinetic particle model of matter made up of?
tiny particles that are in continuous motion.
define internal energy
an energy store that is made up of the total kinetic energy associated with the random motion of the particles and the total potential energy between the particles in the system.
what is the arrangement and motion of solid particles?
arrangement: particles are closely packed and arranged in a regular pattern. particles in solids have the least energy among the three states of matter.
motion: particles vibrate about fixed positions, held together by strong forces of attraction between the particles.
what is the arrangement and motion of liquid particles?
arrangements: particles are slightly less closely packed than in solids and arranged in an irregular pattern.
motion: particles slide over each other throughout the liquid without fixed positions, the forces holding the particles together are weaker than in a solid.
what is the arrangement and motion is gas particles?
arrangement: particles are far apart from one another in an irregular pattern. particles in gasses have the most energy out of all three states of matter.
motion: particles can move freely in any direction. the attractive forces between particles are very weak.
when the average kinetic energy of the particles in a body increases, what increases along with it?
the temperature (can happen vice versa also)
what is thermal equilibrium?
a state in which two or more objects have the same temperature and that there is no net transfer of energy between them
define conduction
a process of energy transfer where energy is transferred through the passing on of vibrational motion form one particle to another.
define convection
a process of energy transfer by means of convection currents of a fluid(liquid of gas), due to a difference in density.
define radiation
the process of energy transfer by electromagnetic waves, does not require a medium
define radiation
the process of energy transfer by electromagnetic waves, does not require a medium
what is a wave
a wave is a series of periodic disturbances that propagates through space, transferring energy from one place to another with it but not matter.
what is a transverse wave?
a transverse wave has a direction of vibration that is perpendicular to the direction of wave travel. (left to right)
what is a longitudinal wave?
a longitudinal wave has a direction of vibration that is parallel to the direction of wave travel(forward)
what is a wavefront?
an imaginary line joining all the adjacent(highest) points that are in phase
frequency lower-higher name the type of electromagnetic waves
rich-man-in-violet-underwear-Xtremely-gay
radio waves, microwaves, infrared waves, visible light, ultraviolet waves, X-rays, gamma rays
all electromagnetic waves are ? waves
transverse
can all electromagnetic waves travel without a medium?
yes
what is the speed of all electromagnetic waves?
3x10^8 m/s
how do we calculate wave speed?
v=fx(upside down F)(dont have the letter
name 4 things radio waves are used for
communication, radio and television broadcasting, radio astronomy, radio frequency idenitification.
name 5 things microwaves are used for.
cooking, communication, radar, cancer treatment, global positioning system (gps)
name 5 things microwaves are used for.
cooking, communication, radar, cancer treatment, global positioning system (gps)
name 6 things infrared is used for?
cooking or keeping warm, data transfer, remote controls, camera auto focusing, infrared greenhouses
name 5 things visible light is used for
photography, telecommunication and medicine, artificial light for plant growth, hardening or curing materials, induced chemical reaction
name 3 thing ultraviolet rays can be used for.
disinfection and sterilisation, vitamin D production, anti-forgery features
name 4 things X-rays can be used for.
X-ray Imaging, computed tomography, security scanning, quality control in manufacturing
name 3 things gamma rays can be used for
disinfection and sterilisation, quality control in manufacturing, radiotherapy
name 3 things gamma rays can be used for
disinfection and sterilisation, quality control in manufacturing, radiotherapy
