Velocity
- Distance/Time (d/t)
- Units: ms^-1
- Rate of change of displacement, speed in a particular direction
Acceleration
- Velocity/Time (v/t)
- Units: ms^-2
- Rate of change of velocity
Four Kinematics Equations
- v = u + at
- v^2 = u^2 + 2as
- s = ((u + v)/2) x t
- s = ut + 1/2 at^2
Weight Force
- Mass x Gravity (W = mg)
- Force on a body due to a gravitational field
Force
- Mass x Acceleration (F = ma)
- Force is the rate of change of momentum (p/t)
- For a Hookes Law Spring (F = Kx)
- The rate of change of momentum of a body
Momentum
Mass x Velocity (P = mv)
Torque
2Fd, where d is the distance from the point of which the object rotates to the force that is being applied.
Work Done
Force x Distance (W = Fd) The distance is in the direction of which the force is applied.
Elastic Potential Energy
Mass x Height x Acceleration due to gravity (Ep = mgh)
OR for a Hookes Law Spring
1/2 x Spring Constant x Extension (1/2kX^2)
Kinetic Energy
1/2 x Mass x Velocity^2 (Ek = 1/2mv^2)
Stress
Force/Area (o = F/A) where the area is equal to the cross-sectional area of the wire
Strain
Extension/Original Length (e = x/L)
Young's Modulus for a Hookes Law Spring
Stress/Strain (E = o/e)
Power
- Work Done/Time (P = W/t)
- Force x Velocity (P = Fv)
- Power is the rate of change of work done with respect to time
Density
- Mass/Velocity (p = m/v)
Pressure
- Force/Area (P = F/A)
- Density x Force of Gravity x Height (P = pgh) where 'p' is equal to density
Velocity of a Wave
- Frequency x Wavelength (v = f?)
Youngs Modulus Slits Experiment Equation
- Wavelength = Distance between slits x Average fringe separation/Distance from slits to screen (? = ax/D)
Diffraction Separation
- Order of Diffraction x Wavelength = Distance between lines x Sin(Angle between lines) (n? = dsinx)
Frequency of a Wave
1/Time (F = 1/t)
Voltage
- Work/Charge (V = W/Q)
- Current x Resistance (V = IR)
Charge
- Current x Time (Q = It)
Resistance
Resistivity x Length/Area (R = pL/A)
Power
- Voltage x Current
- Current^2 x Resistance
- Voltage^2/Resistance
Electromotive Force
- Potential Difference across r (Internal Resistance) + Potential Difference across R (A Resistor) (E = Ir + IR)
Total Resistance in a Series Circuit
- Resistor 1 + Resistor 2 + Resistor 3 + ....... (Rs = R1 + R2 + R3 + .....)
Total Resistance in a Parallel Circuit
- 1/Resistor 1 + 1/Resistor 2 + 1/Resistor 3 + ...... (1/Rp = 1/R1 + 1/R2 + 1/R3 + .......)
Systematic Error
- An error or uncertainty that has a constant value, is due to apparatus or experimental conditions. Can be allowed for and eliminated. Eg. Zero Error
Random Error
- An error or uncertainty that can be above or below the correct value, due to fluctuations in experimental procedures or conditions
Distance
Length of a path, no direction
Displacement
- Distance moved in a particular direction
Speed
Rate of change of distance
Mass
- A measure of inertia of a body (The reluctance of a body to change its motion)
Newtons 1st Law
- A body will continue in its state of rest or uniform motion in a straight line unless an external, unbalanced force acts upon it.
Newtons 2nd Law
- The acceleration of a body is directly proportional to the amount of force applied and takes place in the direction of the force
Newtons 3rd Law
- To every action force there is an equal and opposite reaction force
Principle Conservation of Momentum
- The total linear momentum of a system is conserved unless an external unbalanced force acts upon it
Elastic
- A collision of which no kinetic energy is lost or converted into other forms
Inelastic
- A collision of which kinetic energy is lost or converted into other forms
Upthrust
- The upwards force that is exerted on a body that is wholly or partially immersed in a liquid due to pressure differences between the top and bottom of the body
Scalar
- A physical quantity that has magnitude but no direction
Vector
- A physical quantity that has both a magnitude and a direction
Centre of Gravity
- The point on a body through which the weight effectively acts
Moment of a Force
- Magnitude of a Force x Perpendicular distance between the pivot and the force
Torque of a Couple
- Force x Distance between the 2 forces
Equilibrium
- The point where the sum of all forces about a point = 0 and the total moment about the forces is also = 0
Principle of Moments
- The sum of all clockwise moments are = to the sum of all anti-clocwise moments are
Work
- The product of the force acting on an object and the distance moved by the object in that direction