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In a real machine why is the work output always less than the work input?
Wiki User
∙ 9y ago
Every real machine is subject to forces that reduce output. These include actual forces such as friction, or human controlled forces such as imperfect machining. This reduces the output to less than the ideal.
Wiki User
∙ 9y ago
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Why input current of USis less than Output current?
Why input current of USis less than Output current?
What are the three classes of levers and an anatomical example of each one?
First Class Levers The fulcrum is between the input force and the load Always changes the direction of the input force and can be used to increase the force or the distance Second-class levers The load is between the fulcrum and the input force Does not change direction of the input force Output force is greater than the input force. Third-Class lever The input force is between the fulcrum and the load Does not change the direction of the input force Output force is less than input force.
What is the relationship between energy input energy output and energy losses whenever transfer of energy takes place?
Energy input = energy output + losses. Both energy output and losses are usually positive (they might also be zero in some specific cases), meaning that (usually) each of them individually is less than the energy input.
What is the kva for 7.5 hp 3 phase motor for 1 hour?
1 hp is generally around 750 watts, so you can expect a 7.5hp motor at full load to be ~5.6kW.If lightly loaded, the motor will draw less current, thus less wattage. Also, you cannot calculate current directly from the kW rating and voltage (so full load current will not be 5600/230 = 24.3Amps), as motors are not 100% efficient, and do not have 1.0 power factor. I'd expect the full load amperes to be greater than the kw/voltage value by 20-30%.I looked up a Baldor motor stated to be 7.5hp, and it was ~7kVA, 5.6kW at full load.Another AnswerYou don't specify whether you want to know the machine's output power or its input power.The rated power of a motor is always its output power. In North America, this is expressed in horsepower whereas, in the rest of the world, this is expressed in watts (in practice, kilowatts). As 746 W is equivalent to 1 horsepower, then a 7.5 horsepower motor is equivalent to 5.6 kW.If you wish to determine the rated input power to a machine, which is always larger than its output power, then you must know its efficiency at its rated output power. Divide the output power by the efficienty (expressed as a per unit value).
Why a normal machine could not have the mechanical efficiency of 100?
Because there is always going to be friction, the efficiency of any machine will always be less then 100 percent.
Why is the work output of a machine always less than the work input?
In a real machine, the output work is always less because input energy will be converted to heat energy and lost.
Why is the output work always less than the input work for a real machine?
because output work is input work divided by two
What is the reason a machine's output work is always less than the input force?
Entropy.
Why in a real machine the output work is always less the input work?
In a real machine, part of the energy (or power) is always wasted.
Is the work output always less than the work input when a machine is used to perform a task?
yes
What is meant by efficiency of a machine?
It is the output energy compared to the input energy. This will always be less than 100%
Why is work output by a machine always less than the work input?
It is usually unavoidable that some energy is wasted.
How is the work output of a machine related to it's work input?
In an ideal universe, where there are no friction or heat transfer losses, work out = work in. In our universe, however, work output is always less than input. How much less depends on the efficiency of the machine's design.
Explain why the amount of work that a machine does is less than the amount put into the machine?
Output work is always less than input work.
Is it true that work output of a machine is always less than work input because of energy lost due to friction?
Yes this it true, because a percent of the input energy is converted to heat, which causes the output to became less than the input.
What causes the output work of a machine to be less than the input force?
Some of input energy is wasted in heating up the molecules, sound,etc therefore the resultent output work is always less than the input force due to loss of energy.
Why is the output work in a machine always less than the input work?
Every real machine is subject to forces that reduce output. These include actual forces such as friction, or human controlled forces such as imperfect machining. This reduces the output to less than the ideal.
