Boom

Measurements
Accuracy: Measurements have errors if the systematic error is small.
Frame of reference: A set of rulers and synchronized clocks that are used by observers who are at rest in the frame to describe the motion of an object.
Fundamental units: The kilogram, metre, second, kelvin, mole, ampere, and candela. All other units are combinations of these and are called derived units.Precision: Measurements have precision if the random error is small.
Random error: An error due to incorrectly calibrated instruments. It is the same for all data points and cannot be reduced by repeated measurements.
Vector: A physical quantity with magnitude and direction (e.g. force).
Mechanics
Acceleration: The rate of change with time of the velocity vector. It is a vector. Its magnitude isgiven by the gradient of a graph of velocity versus time.
*Centrifugal force: There is no such thing. Students erroneously include such a force to point away from the centre of a circular path. But the body is not in equilibrium and so no such force is needed.
Centripetal acceleration: The acceleration due to a changing velocity direction. It points toward the centre of the circular path andequalsv2r.
Centripetal force: The name of any force or resultant of individual forces those points toward the centre of a circular path.
Displacement: The distance in a given direction from a fixed origin. It is a vector.
Efficiency: The ratio of useful output work (or power) to input work (or power).
Energy conservation: Energy cannot be destroyed or created. It can be transformed from one forminto another. The mechanical energy of a system (kinetic plus gravitational potential plus elastic potential energy stays the same in the absence of dissipative (frictional) forces.
Equipotential surface: The set of points that have the same gravitational potential.
*Escape speed: The minimum speed an object must have (at the surface of a planet) so that it can move an infinite distance away,v=2GMr.
*Gravitational field strength: The gravitational force experienced by a point test particle of unit mass. The field strength due to a spherical or point mass M is g=GMr2. It is a vector.
*Gravitational potential: The work done in bringing a point test particle of unit mass from infinity to a point in a gravitational field. In the gravitational field of a spherical or point mas M, thepotential is V= - GMr. It is a scalar.
*Gravitational potential energy difference: In mechanics, the work that must be done in order to raise a mass m by a vertical distance ∆h. It is given by ∆EG = mg∆h.
*Gravitational potential energy of two point masses: The work done in moving two point masses M and m, which are initially infinitely far apart, until they are separated by a distance r; it isgiven by ∆EG = - GMmr.
Hooke’s law: The tension in a spring is proportional to its extension and opposite to it: F = -kx.
Impulse: The total change in the momentum of a system as a result of a force acting on it. Its magnitude is given by the area under a force versus time graph. It is a vector.
*Law of gravitation: There is an attractive force between any two point masses, given by F=Gm1m2r2 where r is their separation. It is directed along the line joining the masses.
Momentum conservation: If the net external force on a system is zero, the total momentum of the system stays the same.
Newton’s first law: If the net external force on a system is zero, the system remains at rest or moves with constant velocity.
Newton’s second law: The net force on a body equals the rate ofchange of the body’s momentum. Fnet = dpdt in calculus. When the mass is constant this reduces to Fnet = ma. (For the time intervals that are not infinitesimally small, Fnet = ∆p∆t is the average net force on the body during the time interval ∆t.
Newton’s third law: If body A exerts a force on body B, then body B will exert an equal and opposite force on body A.
*Orbit: The path of an...