Basics of Work, Energy, and Power

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What is the formula for calculating work?

Work is calculated using the formula: Work = Force × Distance × cos(θ), where θ is the angle between the force and the direction of motion.

What are the SI units of work, energy, and power?

The SI unit of work and energy is the joule (J), while the SI unit of power is the watt (W).

Define kinetic energy and provide its formula.

Kinetic energy is the energy of an object due to its motion, calculated by the formula: KE = 0.5 × m × v², where m is mass and v is velocity.

What is potential energy and how is gravitational potential energy calculated?

Potential energy is stored energy due to an object's position or state. Gravitational potential energy is calculated as PE = m × g × h, where m is mass, g is the acceleration due to gravity, and h is the height above a reference point.

Explain the law of conservation of energy.

The law of conservation of energy states that energy cannot be created or destroyed; it can only be transferred or converted from one form to another.

What is the formula for power, and what does power measure?

Power is measured as the rate of doing work or transferring energy, calculated with the formula: Power = Work / Time or Power = Energy / Time.

What is mechanical energy?

Mechanical energy is the sum of kinetic and potential energy in a system due to its motion and position.

Provide an example of conversion between kinetic and potential energy.

A roller coaster at the top of a hill has maximum potential energy, which converts to kinetic energy as it descends.

What impact does friction have on work and energy?

Friction opposes motion, resulting in energy loss often converted to heat, reducing the net work done by an applied force.

How can the power output of an engine be increased?

Power output can be increased by boosting the work done or reducing the time taken to do the work.

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