#### Power voltage equation

## What is the formula for power?

Power equals work (J) divided by time (s). The SI unit for power is the watt (W), which equals 1 joule of work per second (J/s). Power may be measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute, which equals 745 watts of power.

## What is the equation for power current and voltage?

In other words, Energy = power x time and Power = voltage x current. Therefore electrical power is related to energy and the unit given for electrical energy is the watt-seconds or joules. Electrical power can also be defined as the rate of by which energy is transferred.

## How is power rating calculated?

Multiply the value for the current by the value for the voltage to determine the power rating. This quantity will be resolved in units of wattage (watts).

## What is the 5 rule in physics?

The purpose of the 5% Rule is to give you the option of eliminating a vertical axis intercept. When you have a vertical axis intercept that you believe exists only because of error in your data, the 5% Rule can be invoked (if all conditions are met) and the intercept may be dropped from you mathematical equation.

## What is average power formula?

If the resistance is much larger than the reactance of the capacitor or inductor, the average power is a dc circuit equation of P=V2/R, where V replaces the rms voltage. An ac voltmeter attached across the terminals of a 45-Hz ac generator reads 7.07 V.

## What is the equation for current?

Current is usually denoted by the symbol I. Ohm’s law relates the current flowing through a conductor to the voltage V and resistance R; that is, V = IR. An alternative statement of Ohm’s law is I = V/R.

## What is the SI unit of power?

Derived quantity | Name | Expression in terms of SI base units |
---|---|---|

force | newton | m·kg·s^{–}^{2} |

pressure, stress | pascal | m^{–}^{1}·kg·s^{–}^{2} |

energy, work, quantity of heat | joule | m^{2}·kg·s^{–}^{2} |

power, radiant flux | watt | m^{2}·kg·s^{–}^{3} |

## What is the rate of power?

Power is the rate at which work is done. The SI unit for power is the watt (W), where 1 watt equals 1 joule/second (1 W=1 J/s). Because work is energy transfer, power is also the rate at which energy is expended.

## What is the equation for efficiency?

Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula r=P/C, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.

## What is output power?

Power is a scalar quantity. The output power of a motor is the product of the torque that the motor generates and the angular velocity of its output shaft. The rate at which a light bulb converts electrical energy into light and heat is measured in watts – the electrical energy used per unit of time.

## What is the five percent rule in chemistry?

In calculating the pH of a weak acid or a weak base, use the approximation method first (the one where you drop the ‘minus x’). Then apply the 5% rule. If you exceed 5%, then you would need to carry out a calculation that does not drop the ‘minus x. ‘ This would result in quadratic equation, which would be solvable.

## What does Y MX B mean in physics?

In the equation of a straight line (when the equation is written as “y = mx + b”), the slope is the number “m” that is multiplied on the x, and “b” is the y-intercept (that is, the point where the line crosses the vertical y-axis). This useful form of the line equation is sensibly named the “slope-intercept form”.