Tag: types of energy
Questions Related to types of energy
The law of conservation of energy implies that the:
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Total mechanical energy is conserved
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Total kinetic energy is conserved
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Total potential energy is conserved
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Sum of all kinds of energies is conserved
Law of conservation of energy implies that energy can neither be created nor destroyed, but can merely be transfered from one form to other. These forms are varied. Thus, when considering all forms of energy,(including workdone) the total sum never changes.
Energy conservation law says that:
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Energy can't be destroyed but can be produced.
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Neither energy can be produced nor can be destroyed.
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Energy can't be produced but can be destroyed.
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Energy can be produced and can be destoyed
In physics, the law of conservation of energy states that the total energy of an isolated system remains constant—it is said to be conserved over time. Energy can neither be created nor destroyed; rather, it transforms from one form to another.
The speed of a car of mass 1000 kg is reduced from 20 m/s to 10 m/s. What is the work done by the brakes of the car?
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150 kJ
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120 kJ
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100 kJ
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80 k J
Work done by the brakes of a car will be the net change in the kinetic energy of car
$W=\dfrac{1}{2}m({v _2}^2-{v _1}^2)$
$W=\dfrac{1}{2}m({10}^2-{20}^2)$
$W=\dfrac{1}{2}m(100-400)$$=$$\frac{1}{2}1000(-300)$
$W=-150000J=-150KJ$
Hence, option A is correct.
When a stone falls freely towards the earth, its total energy ?
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First decreases and then becomes zero
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Remains constant
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Increases
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Decreases
Since the ball is in free-fall, the only force acting on it is gravity. Therefore, we can use the principle of conservation of mechanical energy - initially the ball has potential energy and no kinetic energy. As it falls, its total energy (the sum of the KE and the PE) remains constant and equal to its initial PE.
Hence, option B is correct.
In which one of the following is electrical energy is converted to light energy?
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Radio
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Fan
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Television
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Electric iron
The machine in which electrical energy is converted to light energy is television.
A steam engine converts
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Chemical energy into heat energy
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Heat energy into mechanical energy
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Chemical energy into mechanical energy
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Mechanical energy into heat energy
A steam engine converts heat energy into mechanical energy.
When an object falls freely towards the earth, then its total energy :
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Increases
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Decreases
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Remains constant
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Can't say
Since the ball is in free-fall, the only force acting on it is gravity. Therefore, we can use the principle of conservation of mechanical energy - initially the ball has potential energy and no kinetic energy.
As it falls, its total energy (the sum of the KE and the PE) remains constant and equal to its initial PE.
Hence, option C is correct.
According to law of conservation of energy :
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Energy can be created but not destroyed and it can be transformed from one form into another
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Energy exists in only one form
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Energy exists in many forms but it cannot be transformed
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Energy can neither be created nor be destroyed but can change into different forms
The law of conservation of energy states that in a closed system the total amount of energy is conserved and does not change. This means that energy may change from one form to another, but that the total amount of energy in the closed system remains constant.
What is law of conservation of energy?
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Energy can neither be created nor destroyed. It can only be transformed from one to another.
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Energy can only be created nor destroyed. It can only be transformed from one to another.
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Energy can neither be created but can be destroyed. It can only be transformed from one to another.
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None
Energy can neither be created nor destroyed. It can only be transformed from one to another is the law of conservation of energy. For example , object falling from certain height converts its potential energy to kinetic energy and at all instant total mechanical energy remains constant.
When you push a huge rock with all your might and fail to move it,then:
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transfer of muscular energy to stationary rock does not take place
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low transfer of muscular energy to stationary rock take place
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high transfer of muscular energy to stationary rock take place
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none
Transfer of muscular energy to stationary rock does not take place as the displacement is zero so the work done by you is zero, avoiding any conversion of energy.