#### Physics power equation

## How do you calculate power in physics?

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 formula for power?

Ohm’s law equation (formula): V = I × R and the power law equation (formula): P = I × V. P = power, I or J = Latin: influare, international ampere, or intensity and R = resistance. V = voltage, electric potential difference Δ V or E = electromotive force (emf = voltage).

## What is the equation for energy in physics?

The formula that links energy and power is: Energy = Power x Time. The unit of energy is the joule, the unit of power is the watt, and the unit of time is the second.

## 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 the SI unit of power?

watt

## What is the efficiency formula?

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.

## How do you calculate total power?

Power can also be calculated using either P = IV or P=V2R P = V 2 R , where V is the voltage drop across the resistor (not the full voltage of the source). The same values will be obtained.

## 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.

## Can power be negative physics?

The sign of power is just a matter of definition. Energy can increase or decrease, but the energy itself cannot be negative. As you said, power is just the time rate of change of energy, so it can be negative. But energy is only positive.

## What is joules formula?

In equation form: work (joules) = force (newtons) x distance (meters), One joule is defined as the amount of work done when a force of one newton is exerted through a distance of one meter.

## How do you find work physics?

Work can be calculated with the equation: Work = Force × Distance. The SI unit for work is the joule (J), or Newton • meter (N • m). One joule equals the amount of work that is done when 1 N of force moves an object over a distance of 1 m.

## 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”.

## 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.