PowerPoint in the classroom

    Cell Biology Education
    |November 5, 2004
    PubMed

    Related Concept Videos

    Power01:08

    Power

    The concept of work involves force and displacement; meanwhile, the work-energy theorem relates the net work done on a body to the difference in its kinetic energy, calculated between two points on its trajectory. While none of these quantities or relations involves time explicitly, we know that the time available to accomplish work is often just as important as the amount of work itself. For example, sprinters in a race may have achieved the same velocity at the finish, therefore,...
    Pascal's Law01:04

    Pascal's Law

    In 1653, the French philosopher and scientist Blaise Pascal published "Treatise on the Equilibrium of Liquids," which discussed the principles of static fluids. A static fluid is a fluid that is not in motion. When a fluid is not flowing, we say that the fluid is in static equilibrium. If the fluid is water, we say it is in hydrostatic equilibrium. For a fluid in static equilibrium, the net force on any part of the fluid must be zero; otherwise, the fluid will start to flow. Pascal observed...
    Power in an AC Circuit01:26

    Power in an AC Circuit

    In a DC circuit, the power consumed is simply the product of the DC voltage times the DC current, given in watts. However, the power consumed for AC circuits with reactive components is calculated differently. Since electrical power is the "rate" at which energy is used in a circuit, all electrical and electronic components and devices have a safe operating range for electrical power.
    In a DC circuit, there is no sinusoidal waveform associated with the supply; the voltages and currents are...
    Power and Energy01:12

    Power and Energy

    The power and energy delivered to an element are subjects of great significance in the field of electrical engineering. It is a well-known fact that a 100-watt light bulb emits more light than a 60-watt one. Therefore, power and energy calculations play a crucial role in the analysis of electrical circuits.
    Power, defined as the time rate of expending or absorbing energy, is quantified in units called watts (W). The relation between power and energy is mathematically given as
    Instantaneous Power01:22

    Instantaneous Power

    Instantaneous power is important in electrical circuits, mainly when dealing with sinusoidal input. Instantaneous power, denoted as p(t), results from the multiplication of the instantaneous voltage (v(t)) across an element and the instantaneous current (i(t)) flowing through it. This relationship adheres to the passive sign convention and represents a fundamental principle in electrical engineering.
    The Power Superposition Principle01:19

    The Power Superposition Principle

    Consider a circuit with two sinusoidal voltage sources. Each one influences the circuit independently, and the superposition principle helps us understand the combined effect by adding up the responses from each source.