Motion, forces and energy Flashcards
Section 1 in the syllabus for cmabridge IGCSE physics
Formula: Average speed (ms^-1) (m/s)
distance(m) / time(s)
Formula: Average velocity (ms-1) (m/s)
displacement(m) / time (s)
Period of a pendulum (s)
total time(s) / no. of swings
Acceleration (ms^-2) (m/s^2)
( final - inital velocity(m/s) ) / time(s)
Weight (N)
Mass(kg) * Gravitational field strength (g)
Force (N)
Mass(kg) * Acceleration (ms^-2)
Density (kgm^-3) (kg/m^3)
Mass(kg) / Volume(m^3)
Hooke’s law in an equation
Force(N) = Consnat (Nm^-1) * Extension(m)
Force(N) ∝ Extension(m)
State Hooke’s law in words
The extension of a spring and the load applied to it are directly proportional until the limit of proportionality is exceeded
Describe, qualitatively, the motion in a circular path
due to a force perpendicular to the motion as
(a) speed increases if force _____ , with mass
and radius constant
(b) radius decreases if force _____ , with mass
and speed constant
(c) an increased mass requires an _____ force
to keep speed and radius constant
(a) speed increases if force increases, with mass
and radius constant
(b) radius decreases if force increases, with mass
and speed constant
(c) an increased mass requires an increased force
to keep speed and radius constant
Describe solid friction
The force between two
surfaces that may impede motion and produce
heating
Describe the moment of a force
A measure of the force’s turning effect
Pressure(Pa)
Force(N) / Area(m^2)
Fluid pressure(Pa)
Density(kg/m^3) * Gravitantionl field strength(ms^-2 or Nkg^-1) * Height(m)
Work(J)
Force(N) * Distance moved(m)
Power(W)
Work(J) / Time(s)
Kinetic energy(J)
1/2 * Mass(kg) * Velocity^2(m/s)
Gravitational potential energy
Mass(kg) * Gravitational field strength(m/s^2) * Height(m)
Efficiency (%) of power
[Useful power output(W)/Total power input(W)] * 100
Efficiency (%) of energy
[Useful energy output(W)/Total energy input(W)] * 100
Moment(Nm)
Force(N) * Perpendicular distance from pivot(m)
Force(N) relating to momentum
Change in momentum(kgm/s) / Time(s)
Momentum
Force(N) * Velocity(m/s)
Impulse(kgm/s or Ns)
Final momentum(kgm/s) - Inital momentum(kgm/s)
Centripetal force(N)
[Mass(k) * Velocity^2(m/s)] / Radius(m)
Orbital period(s)
[2π * Radius(m)] / Velocity(m/s)
Change in gravitational potential energy
Mass(kg) * Gravitational field strength(m/s^2 or N/kg) * Change in height(m)
Power in terms of energy
Change in energy(J) / Time(s)