Equations Flashcards
What is the equation for thinking distance?
Thinking Distance = Reaction Time x Speed of the Car
What are the SUVAT equations?
v=u+at
s=ut+1/2at²
s=vt-1/2at²
s=1/2(u+v)t
v²=u²+2as
What equation relates force, mass and acceleration?
F = ma
Force (N) = Mass (kg) x Acceleration (ms-2)
How is the weight of an object calculated?
W = mg
Weight (N) = Mass (kg) x Gravitational force (ms-2)
How is the moment of a force determined?
M = Fd
Moment (Nm) = Force (N) x Perpendicular Distance of the Line of Action of Force from the Point of Rotation (m)
How is torque calculated?
T = Fx
Torque (Nm) = Perpendicular Separation Between Forces (m) x One of the Forces (N)
How is density calculated?
ρ = m/v
Density (kgm-3) = Mass (kg)/Volume (m3)
How is pressure calculated?
P = F/A
Pressure (Pa or Nm-2) = Force (N)/Area (m2)
What is the equation used to calculate the pressure exerted by a vertical column of liquid?
P = hρg
Pressure (Pa or Nm-2) = Height (m) x Density (kgm-3) x Acceleration by Free Fall (ms-2)
What is an expression for calculating upthrust?
U = vρg
Upthrust (N) = Volume of Liquid Displaced (m3) x Density of Liquid (kgm-3) x Acceleration due to Gravity (ms-2)
How is efficiency calculated?
Efficiency (%) = (useful output energy/total input energy) x 100
How is power defined as an equation?
P = E/t
Power (W) = Work Done (J)/Time (s)
What is an expression relating power and constant speed?
P = Fv
Power (W) = Force (N) x Constant Speed (ms-1)
How is gravitational potential energy calculated?
GPE = mgh
GPE (J) = Mass (kg) x Gravitational Field Strength x Change in Height (m)
How is kinetic energy calculated?
KE = 1/2mv²
KE (J) = 1/2 x Mass (kg) x Velocity² (ms-1)