• Frost Heave

    When water expands it freezes. People in every country where the winters are severe will have experienced the consequences - water freezes in pipes, producing cracks, usuall at points where pipes join or a pipes meets a fitting. Cold stores used to...

    https://astarmathsandphysics.com/o-level-physics-notes/166-frost-heave.html

  • The Importance of the Anomalous Expansion of Water for Life on Earth

    When the temperature falls below 0°C, water freezes. The surface freezes first. Unlike most materials, for which the solid is denser than the liquid form, ice is less dense than water. Ice will not sink in water. Even more strange, as water is heated...

    https://astarmathsandphysics.com/o-level-physics-notes/176-the-importance-of-the-anomalous-expansion-of-water-for-life-on-earth.html

  • The Intensity and Loudness of Sound

    The intensity of a sound wave is defined as 'the rate of flow of energy per unit area perpendicular to the direction of the wave'. It may be shown that the intensity of a sound wave is proportional to the density of the air, the square of the frequency...

    https://astarmathsandphysics.com/o-level-physics-notes/177-the-intensity-and-loudness-of-sound.html

  • Manometers

    Manometers measure pressure. It is basically a glass tube closed at one end, the other end open to the atmosphere. The closed end contains a gas, separated from the atmosphere by liquid in a 'U' bend, shown in blue above. The gas in the bulb exerts a...

    https://astarmathsandphysics.com/o-level-physics-notes/188-manometers.html

  • Measuring the Approximate Size of a Molecule

    From chemical studies we know that molecules of oils and fats are longer than they are wide and that one end is attracted to water, If a drop of oil is placed on a water surface it floats and spreads out to form a thin layer with the molecules standing...

    https://astarmathsandphysics.com/o-level-physics-notes/189-measuring-the-approximate-size-of-a-molecule.html

  • The Common Lift Pump

    Pumps were used successfully to raise water from wells long before their action was understood. They consist of a cylindrical metal barrel with a tube at the side near the top to act as a spout. At the bottom of the barrel, where it joins a pipe...

    https://astarmathsandphysics.com/o-level-physics-notes/231-the-common-lift-pump.html

  • Acceleration, Free Fall and Air Resistance

    In the absence of air resistance any body falling freely under gravity falls with a constant acceleration of A graph of speed against time is shown below for the situation where there is no air resistance. The velocity increases by for every second...

    https://astarmathsandphysics.com/igcse-physics-notes/370-acceleration-free-fall-and-air-resistance.html

  • Conducting Electricity - Metals, Semiconductors and Insulators

    Everybody knows that metals conduct electricity. If you apply a voltage, you get a current. Most elements are metals. However the are two other classes of materials – semiconductors and insulators. Which class a material falls into depends on how free...

    https://astarmathsandphysics.com/igcse-physics-notes/381-conducting-electricity-metals-semiconductors-and-insulators.html

  • Constructing an Angle of Thirty Degrees

    We can construct an angle of 30° by first constructing an angle of 60° then bisecting it. To construct an angle of 60° start by drawing a line AB. Open the compass to the same length as AB and put the compass needle at B. Draw an arc as shown. Now put...

    https://astarmathsandphysics.com/igcse-maths-notes/458-constructing-an-angle-of-thirty-degrees.html

  • Curves - Maxima, Minima, Stationary Points and Turning Points

    I don't know why these thing need four possible names. We can call them stationary points and classify them as maxima or minima. Definition: A stationary point is a point on a curve where Definition: A stationary point, with is a Minima if On a graph a...

    https://astarmathsandphysics.com/igcse-maths-notes/466-curves-maxima-minima-stationary-points-and-turning-points.html

  • Solving Exponential Simultaneous Equations Algebraically

    If some quantity is increasing decreasing by the same proportion or factor in each time interval, then it is said to vary exponentially. A good example is money left in a bank which attracts compound interest at the same rate each year. If the rate of...

    https://astarmathsandphysics.com/igcse-maths-notes/520-solving-exponential-simultaneous-equations-algebraically.html

  • Constructing an Angle of Thirty Degrees

    We can construct an angle of 30 ° by first constructing an angle of 60 ° then bisecting it. To construct an angle of 60 ° s tart by drawing a line AB. Open the compass to the same length as AB and put the compass needle at B. Draw an arc as shown. Now...

    https://astarmathsandphysics.com/gcse-maths-notes/572-constructing-an-angle-of-thirty-degrees.html

  • Quantities in Direct and Inverse Proportion

    The two graphs show quantities directly proportional in the first graph and inversely proportional in the second graph. For the first graph we can write down, and for the second graph where, in each case, is a constant of proportionality. We are...

    https://astarmathsandphysics.com/gcse-maths-notes/583-direct-and-inverse-proportion.html

  • Maximising and Minimising Expressions

    Suppose we want to find the maximum distance between two points. We might know where the two point are, but it is in the nature of measurements that they are never exact. A is at 2 to the nearest whole number. This means is must be closer to 2 than any...

    https://astarmathsandphysics.com/gcse-maths-notes/608-maximising-and-minimising-expressions.html

  • The ECG

    An electrocardiogram (ECG) measures the voltage through the heart as it beats. moving through the heart during a heartbeat. The heartbeat is divided into parts, with each part being given an alphabetical label. Each heartbeat begins with an impulse....

    https://astarmathsandphysics.com/gcse-physics-notes/847-the-ecg.html

  • Proof of the Fundamental Theorem of Calculus

    The Fundamental Theorem of Calculus states: For a continuous function with antiderivative Ptoof: Consider a function which has antiderivative and an area function where is the area from to is clearly an increasing function and Now consider a narrow...

    https://astarmathsandphysics.com/ib-maths-notes/calculus/933-proof-of-the-fundamental-theorem-of-calculus.html

  • The Binomial Expansion

    We can use the binomial theorem to expand and simplify expressionsof the form where isany positive whole number. The general expansions is Example: The coefficients gere have a special signifucance. isthe number of ways in which a term with canbe...

    https://astarmathsandphysics.com/ib-maths-notes/counting-permutations-and-combinations/966-the-binomial-expansion.html

  • Summary of Formulae - Conditional Probability, Independent Events etc

    This is only true if A and B are independent. You can never assume A and B are independent. You must either know it or prove it. This is always true for two events A and B. The left hand side P(A divides B) is the probability that A will happen given...

    https://astarmathsandphysics.com/ib-maths-notes/probability-and-statistics/1069-summary-of-formulae-conditional-probability-independent-events-etc.html

  • Quadratics

    A lot of algebra involves deriving equations to represent problems and solving them. A very good example is found from geometry. The right angled triangle below has three unknown sides. Believe it or not, we can find the lengths of the sides knowing...

    https://astarmathsandphysics.com/ib-maths-notes/quadratics/1086-quadratics.html

  • Arithmetic Sequences

    An arithmetic sequence is a series of numbers such that to get the next number in the sequence we add a number to the last term. We add the SAME number each time. For example 4, 9, 14, 19, 24 is an arithmetic sequence because we add 5 to each term to...

    https://astarmathsandphysics.com/ib-maths-notes/sequences-and-series/1114-arithmetic-sequences.html

Results 101 - 120 of 209