semester 1 definitions Flashcards
physical quantities
those quantities that can be measured and can be assigned some units
(length - m
mass - kg
time - s
angle - degree
volume - m^3, L, mL)
scalars
quantities that can be completely defined by magnitudes only (length, time, speed, temperature)
vectors
quantities that can be defined by using both magnitude and direction (force, velocity, acceleration)
distance
path taken between 2 points
displacement
shortest distance between 2 points
speed
change in distance with respect to time (rate of change of distance
velocity
rate of change of displacement (how displacement changes with time)
acceleration
how velocity changes with respect to time
deceleration / retardation
negative acceleration
S
U
V
A
T
S - displacement
U - initial speed
V - final speed
A - acceleration
T- time
stationary
not moving / not changing
s - t graphs
displacement - time graphs
v - t graphs
velocity - time graphs
force (push or pull)
push or pull on an object that attempts to change its motion, shape, or size
inertia
capacity of an object to resist a change in motion from a force
momentum
physical ability, stamina in a weight
friction occurs?
when 1 object is being pulled or pushed while in contact with another object
air resistence
another form of friction that occurs when an object is moving through the air
drag force
the opposing force on the object’s moving through fluids
terminal velocity
the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity (gravity and air resistance is the same)
equilibrium
total force = 0, no change in motion, constant speed or rest or bar in a state of balance
force (state of motion)
brings change in state of motion in an object
moment of a force (description)
rotational effect brought on a body due to application of force
moment of a force (definition)
product of the force and the perpendicular distance from the pivot to the line of action of the force
principle of moments
if a body is not to rotate, the net clockwise moment of a force on it must equal the net anti clock wise moment of a force
center of gravity
the point on a body where the whole of the weight of the object is assumed to be acting
energy
the ability of a body to perform work
principle of conservation of energy
the total energy of a system always remains constant but it can change from 1 form to another
kinetic energy
the energy possessed by moving objects
potential energy
the energy possessed by objects due to their position or configuration
gravitational potential energy
energy possessed by objects due to their height from the surface of the Earth
elastic potential energy
energy possessed by objects due to stretch / energy possessed by strained objects
electric potential energy
the energy acquired by the charged particles in electric field (positive and negative attraction
power
the rate at which energy is transferred, or the rate at which work is done (how fast work is done)
efficiency
how much useful work is done in a given time without wasting much energy
