AS Physics 9702 Definitions and Equations

We have compiled all the definitions and equations of AS Level Physics 9702. To get full handout click here.

• MEASUREMENT TECHNIQUES:

1. Systematic Error: A constant or consistent error in measurement which may be attributed to a fault in the instrument or a consistent flaw in the measuring technique, and which cannot be eliminated by averaging.
2. Random Error: An error of variable magnitude in which the readings are scattered about the true value. This type of error is due to limitations on the part of the observer or an inconsistency in measuring equipment. It can be eliminated by averaging
3. Precision: The degree of refinement with which an operation is performed or a measurement is stated. It relates to how close measurements are to their mean value.
4. Accuracy: The degree of conformity of a measure to a standard or a true

• PHYSICAL QUANTITIES & UNITS:

1. Principle of Homogeneity: states that in a homogenous equation, every expression, on either side of the equation, has the same
2. Homogenous Equation: An equation in which the base units of all quantities added or subtracted is the same on either side of the
3. Physical Quantity: A quantity that has dimension and can be measured.
4. Scalar Quantity: A quantity in which only the magnitude is of significance and does not possess directional
5. Vector Quantity: A quantity possessing both a magnitude and
6. Base Unit: The units for the seven basic physical The following are the seven basic quantities with their respective units:

Basic SI Units

Prefixes

• KINEMATICS:

1. Distance: The length of the path between two It is a scalar quantity and is measured in the SI unit meter (m).
2. Displacement: The shortest distance between two points in a linear direction from a fixed point of It is a vector quantity measured in the SI unit meter (m).
3. Speed: The rate of change of distance. It has the formula and is a scalar quantity measured in the SI unit meter per second (ms-1).
4. Velocity: The rate of change of displacement. It has the formula and is a vector quantity measured in the SI unit meter per second (ms-1).
5. Acceleration: The rate of change of velocity. It has the formula and is a vector quantity measured in the SI unit meter per second square (ms-2).

• DYNAMICS:

1. Newton’s First Law: A body continues in a state of rest or of motion at a constant speed in a straight line unless acted upon by an external
2. Newton’s Second Law: The net force acting on a body of constant mass is directly proportional to the acceleration it gains if no external force is acting on the body. Fnet = ma.
3. Newton’s Third Law: For every action, there is an equal but opposite
4. Mass: The measure of a body’s resistance to changes in its dynamic It is a scalar quantity measured in the SI unit kilogram (kg).
5. Weight: The force a body experiences due to the effect of gravitational acceleration on its mass towards the centre of the earth. It has the formula W = mg and is a vector quantity measured in the special SI unit Newton (N).
6. Linear Momentum: The product of the mass of a body and its velocity. It is a quantity that describes the motion of a body. It has the formula p = mv and is a vector quantity measured in the SI unit Newton second(Ns).
7. Force: The rate of change of momentum of the body upon which it It has the equation F = dp/dt and is a vector quantity measured in the SI unit Newton (N).
8. Principle of Conservation of Momentum: The total momentum of interacting bodies in a closed system remains constant providing that there is no external force acting on
9. Elastic Collision: A collision in which kinetic energy, linear momentum and the total amount of energy are all conserved.
10. Inelastic Collision: A collision in which the bodies coalesce upon impact. The kinetic energy is not conserved but the total amount of energy and linear momentum is conserved.
11. Perfectly Elastic collision: A collision in which the masses of the two bodies colliding are equal and the two bodies interchange their velocities after collision. Kinetic energy, linear momentum and the total amount of energy are all conserved.