physics def Flashcards
(108 cards)
Newton’s First Law of Motion
An object will remain in a constant velocity (or at rest) unless a resultant external force acts upon it.
Centripetal acceleration
The acceleration due to a changing velocity direction. It points toward the centre of the circular path and equals (v^2)/r.
displacement
distance in a specified direction
acceleration
rate of change of velocity
instantaneous velocity
velocity at a moment in time
linear momentum
product of mass and velocity
impulse
force × time
change in momentum
Newton’s second law
the acceleration of a body is proportional to the force applied and inversely proportional to its mass
Newton’s third law
when two bodies A and B interact the force that A exerts on B is equal and opposite to the force that B exerts on A
conservation of linear momentum
the momentum of a system is constant for an isolated system
work
force applied in direction of movement x displacement
conservation of energy
energy cannot be created or destroyed, it just changes form
elastic collision
collision in which momentum and kinetic energy are both conserved
inelastic collision
collision in which only momentum is conserved, kE is lost(transferred)
power
rate of doing work
efficiency
ratio of useful output work to total input work
thermal equilibrium
system of bodies at the same temperature
internal energy
total potential energy and random kinetic energy of the molecules of the substance
thermal energy
non-mechanical transfer of energy between a system and its surroundings
mole
amount of a substance containing same number of particles as atoms in 0.012kg of carbon-12
Avogadro constant
the number of particles in one mole
specific heat capacity
quantity of thermal energy required to raise temperature of unit mass by 1K
thermal capacity
the energy required to raise the temperature of a substance by 1K
evaporation
and boiling
takes place at the surface of a liquid and at any temperature
takes place thoughout the liquid and always at the same temperature