formulas Flashcards
State the principle of moments
For a body in an equilibrium , the total sum of clockwise moments about any point is equal to the total sum of anti-clockwise moments about the same point.
Define Inertia
Inertia is the reluctance of a body to change its state of rest or motion.
Define moment
The moment is the product of the force and the perpendicular distance from pivot to force.
What are the 2 Laws of Reflection
1) The incident ray, the reflected ray and the normal all lie on the same plane.
2) The angle of incidence is equal to the angle of reflection.
Define Heat Capacity
Heat capacity (C) is the amount of thermal energy required to raise the temperature of a substance by 1 K or °C.
Define Specific Heat Capacity
Specific heat capacity (c) is the amount of thermal energy required to raise the temperature of a unit mass (e.g. 1 kg) of a substance by 1 K (or 1°C).
Define Latent Heat
Latent heat is the thermal energy required to change the state of a body from one state to another, at a constant temperature.
What are Longitudinal waves?
Longitudinal waves are waves which travel in a direction parallel to the vibration of particles
What are transverse waves?
Transverse waves are wave which travel in a direction perpendicular to the vibration of particles
Define Focal length
Focal length is the distance between the centre of the lens and the focal point.
What is focal point?
The focal point is a point where a parallel beam of light will converge at after passing through the lens.
What is Newton’s first law?
An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force
What is Newton’s 2nd law
When a resultant force acts on an object of a constant mass, the object will accelerate in the direction of force.
What is Newton’s 3rd law?
Forces always occur in (action-reaction) pairs
State the speed of light in a vacuum
Speed = 3 x 10⁸ m/s
Define Critical Angle
Critical angle is the angle of incidence in the optically denser medium where the angle of refraction in the optically less dense medium is 90°
State the 2 conditions for Total Internal Reflection to occur
1) Light rays travel from an optically denser medium to an optically less dense medium
2) Angle of incidence in the optically denser medium is greater than the critical angle
What is the Law of electrostatics
Like charges repel, unlike charges attract
List the EM waves
(from increasing frequency)
Radiowaves, Microwave, Infrared, Visible light, Ultraviolet, X-ray, gamma ray,
Ronald Mcdonald Is Very Understand Xcept Girls
Define focal length of converging length
distance between optical centre and principal focus of the lens
