Hello,Welcome to StudentBro.
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Hello,Welcome to StudentBro.
Work, energy, and power are fundamental concepts in physics that describe how forces cause motion, how energy is transferred, and how quickly work is done. Understanding these concepts is crucial for solving numerical problems in NEET physics.
Work is said to be done when a force is applied to an object, causing it to move in the direction of the applied force.
The work done (W) by a constant force is defined as the product of the force and the displacement in the direction of the force.
Positive Work: When the force and displacement are in the same direction.
Negative Work: When the force and displacement are in opposite directions.
Zero Work: When there is no displacement or the force is perpendicular to displacement.
In cases where the force is not constant, work is calculated using integration over the path of displacement.
Work Done by Gravity: When an object moves under the influence of gravity.
Work Done by a Spring Force: Work required to compress or stretch a spring.
Work Done by Friction: Negative work as friction opposes motion.
Energy is the capacity to do work. It exists in various forms, such as mechanical, thermal, chemical, and electrical energy.
Mechanical energy is the sum of kinetic and potential energy.
Kinetic Energy: The energy possessed by a body due to its motion.
Potential Energy: The energy stored in an object due to its position or configuration.
The work-energy theorem states that the net work done on an object is equal to its change in kinetic energy. This theorem is essential for solving problems related to force and motion.
The principle of conservation of mechanical energy states that in the absence of non-conservative forces (like friction), the total mechanical energy of a system remains constant.
The gravitational potential energy of an object depends on its height above a reference level.
It is crucial in understanding free-fall motion and energy conversion in pendulums and roller coasters.
The energy stored in a compressed or stretched spring follows Hooke’s Law.
It is used in oscillatory motion and simple harmonic motion.
Power is the rate at which work is done or energy is transferred. It determines how fast work is performed over time.
Average Power: The total work done divided by the total time taken.
Instantaneous Power: The power at a specific moment, found using the derivative of work with respect to time.
Power can also be expressed as the dot product of force and velocity, helping in analyzing motion-related problems.
The SI unit of power is the watt (W).
1 Watt = 1 Joule/second.
Larger units include kilowatt (kW) and horsepower (HP).
Collisions play a crucial role in energy transfer and momentum conservation.
Elastic Collision: Both momentum and kinetic energy are conserved.
Inelastic Collision: Momentum is conserved, but kinetic energy is not.
Perfectly Inelastic Collision: The colliding objects stick together after collision, losing maximum kinetic energy.
In real-world scenarios, some energy is lost as heat, sound, or deformation.
The coefficient of restitution determines the elasticity of a collision.
Hydroelectric dams convert gravitational potential energy into electrical energy.
Vehicles use chemical energy in fuel to generate kinetic energy.
A pendulum’s energy continuously shifts between kinetic and potential energy.
Electrical devices consume power at different rates.
The energy consumed is measured in kilowatt-hours (kWh), used in electricity billing.
Work, energy, and power are fundamental concepts in physics, forming the basis of various real-world applications. Understanding their principles helps in solving complex NEET problems related to mechanics, energy conservation, and motion
