What does specific power mean, what does power mean

Specific power is a comprehensive index to measure the dynamic performance of a car, specifically referring to the engine of the car.

The ratio of the maximum power to the total mass of the car (see the corresponding explanation for the above two concepts). Generally speaking, for the same type of car, the greater the specific power, the better the power of the car.

For example: Volkswagen's Bora and Bora, car appearance, car gross weight and other parameters are similar, but, because the maximum power of the two engines is 110 kilowatts and 78 kilowatts respectively, the specific power is about 84 kilowatts and 60 kilowatts respectively, so there is a large gap between the maximum speed of the two cars.

Power refers to the work done by an object per unit of time.

In physics, power p = work (j) time (t), the unit is watts (w), and the unit of power is often seen.

There are KW, PS, HP, BHP, WHPMW, etc., as well as the CV used in Italy, where the kilowatt (kW) is the international standard unit, 1kW = 1000W, and 1000 joules can be done in 1 second.

The power of the work is 1kw.

In daily life, we often refer to power as horsepower, and the unit is horsepower, just like torque is called torsion.

A method of comparing power

Power is a physical quantity that describes how fast or slow work is done.

The basal plexus is generally compared in one of the following three ways: blindness.

In the same time, compare the amount of work done, the more work done on the object, the greater the power.

Under the condition of completing the same work, compare the length of time, the shorter the time taken for the object, the greater the power.

In the case of different amounts of work done and time spent, a comparison is made by calculating p half.

Power refers to the amount of work done by an object per unit of time, i.e., power is a physical quantity that describes how fast or slow work is done. The amount of work is constant, and the shorter the time, the greater the power value. The formula for finding power is power = power ratio time.

Power is a physical quantity that characterizes the degree of work done fast or slow. The work done per unit of time is called power and is denoted by p. Therefore, the power is equal to the scalar product of the force and the velocity of the point where the object is stressed.

Characteristics of powerPower is the physical quantity of the physical quantity of the work done by the object, the power p = work j than time t, the unit is watt w, we often see the power unit of the first to talk about kw, ps, hp, bhp, whpmw, etc., as well as the cv used to be used in Italy, where the kilowatt kw is the international standard unit, 1kw = 1000w, with 1 second to do 1000 joules of work, its power is 1kw.

The unit of power is the International System of Units and the Chinese legal unit of measurement is watts, which is 1 joule per second of work. 1000 watts is called kilowatts. In daily life, we often refer to power as horsepower, and the unit is horsepower, just like torque is called torque.

Power is the amount of electricity consumed by an appliance in one second.

Electricity consumption is proportional to the length of time spent on electricity. It is specified that the power consumption segment within one second is called power, and the power can be used to explain the speed of power consumption of an electrical appliance. From this, it can be seen that the power consumption is also proportional to the power during the specified time. Namely:

Power consumption: Electrical power, electricity time.

The unit of power is watts (W), the unit of time is hours (h), and the unit of electricity consumption is watt-hours (wh).

The power is 1 watt, and the power consumption for 1 hour is 1 watt-hour. 1000 watt-hours is 1 kilowatt-hour of electricity. That is, 1 kilowatt of power consumes 1 kilowatt of electricity for 1 hour.

1. The calculation method of electricity consumption is as follows: electricity consumption (kW·h) Power (W) 1000x time (hours). No matter what kind of electrical appliances, the manual or nameplate will be marked with the power (watt grip game, represented by the letter W), usually we say how many kilowatts of electricity consumption, one kilowatt hour according to the standard, the concept is the power of 1000 (W) electrical appliances, the electricity consumed in an hour.

2. The amount of electricity indicates the amount of charge carried by the object. Generally speaking, the quantity of electric charge is called the amount of electricity, which is represented by the symbol q, and the unit is the coulomb (the symbol is c), and the coulomb is a very large unit. Without confusion, the amount of charge can simply be called an electric charge.

Specific energy: Also known as energy density.

The electrical energy output of the external work of the battery is the product of the amount of electricity and voltage, and the specific energy is the unit weight or unit volume.

The amount of energy exported by the battery. The unit is Wh kg 1 or Wh L 1.

For example, lead-acid batteries.

Pb ten PBO2 H2SO4 2PBSO4, the active substance is PB, PBO2 H2SO4 total electrification equivalent, K 3 866 4 463 2X1 830 11 989 E E0 ( 2 045 V ) The theoretical specific energy is 170 5Wh kg. The actual specific energy of a lead-acid battery is 10 50Wh kg. Much lower than the theory than the energy.

Specific power: is the specific energy of the battery per unit time. The specific power is a characterization of the operating current that the battery can withstand. If the power is larger, the current can be discharged with a larger current. For example, silver-zinc batteries at medium current densities.

When discharged, the specific power can reach more than 100W kg; And zinc-manganese dry batteries.

When operating at low current densities. The specific power can only reach 10kg.

When current flows out of the positive terminal, it is the output power, and when it flows into the positive terminal, it is the absorbed power.

The following figure: the voltage at the resistor end is 10V (left negative and right positive), and the voltage at the current source end is 15-10=5V (positive and negative).

At this time, the voltage source outputs power, and the current source absorbs power (the voltage at the end of the current source is positive and negative).

Above left: The current flowing into the resistor (flowing from above) 15 5 = 3A, so the current flowing out of the voltage source = 3-2 = 1A, and the voltage source and current source are both output power (the voltage at the end of the voltage source and the current source are both positive and negative, 15V).

Above right: Similar to the left figure, but because the current source is in the opposite direction, the current flowing out of the voltage source is 5A, the output power of the voltage source, and the absorption power of the current source (the voltage at the end of the current source is 15V, negative at the bottom and positive at the top).

Electrical powerThe formula for calculating is that the power work is divided by the time, i.e., p=w divided by t.

2. MachineryPower calculation formula: Power work divided by time, i.e. p=w divided by t, this formula calculates the average power; Power force multiplied by displacement, i.e. p=fv, this formula calculates instantaneous power.

Power is divided into two types: electrical power and mechanical power, so the calculation formula is not the same, and the corresponding formula should be selected according to the type of power.

Physical formulas. Power can be divided into electrical power, power of force, etc. Therefore, the calculation formula is also different.

Power power Electrical power calculation formula: p=w t=ui;

in purely resistive circuits.

, according to Ohm's law.

U=IR substituting P=UI also yields: P=i R=(U) R

In kinetics: power calculation formula: average power); p=fvcos (instantaneous power).

Since w=f(f force) s(s displacement) (the definition of work), the formula for finding power can also be derived from p=f·v:p=w t=f*s t=f*v (this formula is applicable to the uniform linear motion of an object.

P in the formula stands for power, the unit is "watts", abbreviated as "watts", and the symbol is w.

w denotes work. The unit is "joules", abbreviated as "joules", and the symbol is j.

t is the time, the unit is "seconds", and the symbol is s"。

The most full power calculation formulas can be found in Further Reading, where the author summarizes almost all of the commonly used calculation formulas.

The above content refers to Encyclopedia - Power.