For a lever, you can increase the machine’s efficiency
by reducing the friction
.
What makes a machine efficient?
The efficiency of a machine concerns how much energy is lost to friction and heat during its operation. Since work is the change in kinetic energy, the efficiency of a machine can be stated as
the percentage of the output work divided by the input work minus the work lost from to friction and heat
.
How Can machines be made more efficient?
Because all machines lose input work to friction, one way to improve the efficiency of a machine is
by reducing friction
. Oil is used to reduce friction between the moving parts of car engines. The use of oil makes engines more efficient. … Bicycles lose energy to friction and to air resistance.
Is it possible to make a machine completely efficient?
Most machines transfer energy from one place or another, or transform one form of energy (e.g. chemical) into another (e.g. mechanical), but machines can`t create any form of energy. … That is why
100% efficiency in machines shall not be possible
.
What should be done to make simple machine more efficient in points?
Answer:
Friction
is the main factor which reduces the efficiency of a simple machine. Efficiency of a simple machine can be increased by reducing the friction. But oiling and greasing the machine is a useful way to increase the efficiency of a machine.
Is there a machine that is 100% efficient?
No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). … That is why
100% efficiency in machines shall not be possible
.
Why can a machine not be 100% efficient?
A machine cannot be 100 percent efficient because
output of a machine is always less than input
. A certain amount of work done on a machine is lost to overcome friction and to lift some moving parts of the machine.
Why is it impossible to get an efficiency of 100% or greater?
It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics. This is impossible
because some waste heat is always produced produced in a heat engine
, shown in Figure 1 by the term.
Can a machine ever be used to multiply the work done on it?
All machines are subject to energy conservation in that no machine can output more energy (do more work) than the energy put into it. …
Machines cannot multiply energy or work input
. To say that a machine has a certain mechanical advantage tells you how much the machine multiplies input force.
Can a machine multiply an input force?
A
machine can multiply force and it can multiply distance
. However, it cannot multiply input energy because this would violate the law of conservation of energy.
What can simple machines not do?
A machine
cannot increase the amount of energy you put into it
. So, why is a simple machine useful? Although it cannot change the amount of work you do, a simple machine can change the amount of force you must apply to an object, and the distance over which you apply the force.
How much energy will be wasted on using a simple machine with efficiency 80%?
Explanation: It means that the machine converts 80% of input energy into output or useful energy and remaining
20% energy
is wasted due to friction.
What are 1st 2nd and 3rd class levers?
–
First class levers have the fulcrum in the middle
. – Second class levers have the load in the middle. – This means a large load can be moved with relatively low effort. – Third class levers have the effort in the middle.
Why is it impossible to get a perfect machine in practice?
A machine whose
efficiency is 100%
is practically impossible to make as a 100% efficient machine has 0 mass and has 0 friction between its parts, which is impossible to achieve.
Which machine has highest efficiency?
The most efficient electrical machine is the
transformer
. Transformers have efficiency above 95%. The autotransformer has an efficiency of close to 98%.
Why the efficiency of a machine is less than 1?
Since a machine does not contain a source of energy, nor can it store energy, from conservation of energy the power output of
a machine can never be greater than
its input, so the efficiency can never be greater than 1.
