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How do you calculate power from potential difference?
For any circuit element, the power is equal to the voltage difference across the element multiplied by the current. By Ohm’s Law, V = IR, and so there are additional forms of the electric power formula for resistors. Power is measured in units of Watts (W), where a Watt is equal to a Joule per second (1 W = 1 J/s).
How do I calculate kinetic energy?
In classical mechanics, kinetic energy (KE) is equal to half of an object’s mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.
What is the formula for kinetic and potential energy?
At a start, the potential energy = mgh and kinetic energy = zero because its velocity is zero. Total energy of the object = mgh. As it falls, its potential energy will change into kinetic energy. If v is the velocity of the object at a given instant, the kinetic energy = 1/2mv2.
How do you find the kinetic energy of a pendulum?
Ignoring friction and other non-conservative forces, we find that in a simple pendulum, mechanical energy is conserved. The kinetic energy would be KE= ½mv2,where m is the mass of the pendulum, and v is the speed of the pendulum. At its highest point (Point A) the pendulum is momentarily motionless.
How are voltages converted in a power adapter?
Power adapters convert the electricity from one voltage to another voltage, and sometimes between AC and DC. The quick answer to your question is to multiply the INPUT voltage by the INPUT current. In this case, you likely have 120 V input (if you’re in the United States).
How to calculate the wattage of an AC adapter?
If you want to calculate the total amount of power (called “wattage”) that an AC adapter uses, you can do so using information present on the informational label on the adapter itself. Look at the identification label on the side of your AC adapter. Write down the total number of volts and the total amperage the AC adapter uses.
How much power does a power adapter use?
In your example, the power adapter is rated to use a maximum of 58 W (0.24*240), but can output only 5*1.5=7.5 W. So, worse case based on the label, it will use 58 W, but only supply 7.5 W to your device, so about 13% efficient.
What’s the difference between the input and output of a DC adapter?
The INPUT is what sort of electrical system you need to supply to the adapter (i.e. what your power company supplies). The OUTPUT is what is supplied to your device. Note that he amount of DC electrical power is calculated by multiplying the current by the voltage (P=I·V).