This chapter explains the concepts of work, energy, and power, which are essential for understanding physical systems.
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WORK, ENERGY AND POWER - Flash Cards
These flash cards cover important concepts from WORK, ENERGY AND POWER in Physics Part - I for Class 11 (Physics).
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What is the definition of work in physics?
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In physics, work is defined as the product of the force applied on an object and the displacement of that object in the direction of the force. Formula: W = F × d × cos(θ), where θ is the angle between the force and displacement vectors.
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What is the SI unit of work?
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The SI unit of work is the Joule (J). One Joule is defined as the work done when a force of one newton displaces an object by one meter in the direction of the force.
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What is energy in physics?
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Energy is the capacity to do work. It exists in various forms such as kinetic energy, potential energy, thermal energy, etc.
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What is the formula for kinetic energy?
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The formula for kinetic energy (KE) is KE = (1/2)mv², where m is mass and v is the velocity of the object.
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Define potential energy.
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Potential energy is the energy possessed by an object due to its position or configuration. For gravitational potential energy: PE = mgh, where m is mass, g is acceleration due to gravity, and h is height above a reference point.
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What does the work-energy theorem state?
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The work-energy theorem states that the work done by the net force acting on an object is equal to the change in its kinetic energy.
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How is power defined in physics?
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Power is defined as the rate at which work is done or energy is transferred. Formula: Power = Work done / Time taken.
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What is the SI unit of power?
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The SI unit of power is the Watt (W). One Watt is equal to one Joule per second.
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What is the scalar product of two vectors?
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The scalar product (or dot product) of two vectors A and B is given by A · B = |A||B| cos(θ), where θ is the angle between the vectors. It results in a scalar quantity.
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What is the commutative property of the scalar product?
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The scalar product follows the commutative property: A · B = B · A.
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State the distributive property of the scalar product.
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The distributive property states: A · (B + C) = A · B + A · C.
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What is the scalar product of two perpendicular vectors?
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If two vectors A and B are perpendicular, then A · B = 0.
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How to calculate work done in lifting an object?
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The work done in lifting an object is calculated using W = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height lifted.
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What is the principle of conservation of energy?
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The principle states that energy cannot be created or destroyed, only transformed from one form to another.
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What is the difference between work and energy?
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Work is the transfer of energy through force applied over a distance, while energy is the capacity to perform work.
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Provide an example illustrating power.
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Running up the stairs quickly requires more power than walking up because power is the rate of doing work; more work is done in less time.
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Is work done when force is applied but no movement occurs?
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No, work is only done when an object moves in the direction of the applied force. If there is no displacement, work done is zero.
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What is the relation between work and energy?
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Work done on an object results in a transfer of energy to that object, changing its kinetic energy or potential energy.