Definitions Flashcards
Parallax
A phenomenon which occurs as a result of having stereoscopic vision (2 eyes which see slightly different things).
Special relativity
An object moving at a speed awhile is close to the speed of light is know as relativistic - no longer follows f=ma and therefore the mass increases.
Newton
The force that causes a mass of 1kg to have an acceleration of 1ms^-2 in the direction of the force.
Kinematics
The field of physics concerning the motion of bodies without any reference to the forces that cause the motion to happen.
Dynamics
The field of physics concerned with the motion of bodies and the forces that cause the motion to happen.
Homogenous
Every term in the equation must have the same physical dimensions (therefore the equivalent units).
Velocity
The displacement per unit time. SI unit: m/s
Vector
A quantity that had magnitude and direction.
Strain
Fractional increase in length - x/l (no unit).
Stress
Force applied per unit cross sectional area (F/A) measured in pa or N/m2
Speed
Distance travelled per unit time
Torque of a couple
One force x perpendicular distance between the forces.
Scalar
A quantity that had magnitude only.
Precise
Only a small variation between repeated readings.
Moment
Force x perpendicular distance from pivot to line of action of force (Nm)
Inelastic
A collision is inelastic if the momentum is conserved but some of the kinetic energy is transferred to other forms in the collision.
Elastic
A collision is elastic if the momentum and the kinetic energy are conserved and no energy is transferred to other forms such as heat or sound.
Density
Mass per unit volume (kg/m3)
Displacement
The distance travelled in a particular direction - a vector quantity
Young modulus
Stress/strain
Centre of gravity
The point at which all the weight of an object appears to act.
Accurate
A value is accurate if it is close to the true value.
Acceleration
Rate of change of velocity (m/s)
Spring constant
Characterised as the ‘stiffness’ of a spring.
Current
Rate of flow of charge. SI unit: A
Amplitude
The maximum displacement of a wave from its rest position
