Wave energy, often referred to as the energy carried by waves, encompasses both the kinetic energy of their motion and the potential energy stored within their amplitude or frequency. This energy is not only essential for natural processes like ocean currents and seismic waves but also holds significant promise for renewable energy generation.
Whenever energy has been transferred, it is always designated according to its nature. This states that energy always changes its form if required like electric energy got converted into light when a bulb is lightened, similarly wind energy can be converted to mechanical and then electrical in windmills.
A wave is a disturbance/ movement of particles in a medium that transports energy without causing net particle movement. Elastic deformation, pressure variations, electric or magnetic field, electronic potential, or temperature variations are all examples.
The main components of wave energy are Kinetic energy and Potential energy.
A string is attached to the rod of the string vibrator, which produces a sinusoidal wave in the string, with a wave velocity v. A section of the string with mass Δm oscillates at the same frequency as the wave.The Formula of Kinetic energy is,
Ukinetic = mv2 / 2
Let v be the velocity of the wave.
Since, velocity has two component vx (horizontal component in direction of motion of wave) and vy (perpendicular component perpendicular to motion of wave).
So, the kinetic energy of each mass element of the string is,
ΔUkinetic = 1/2 (Δm) vy2
as the mass element oscillates perpendicular to the direction of the motion of the wave.
If the density of string is μ, then the mass of element (Δx) of string,
Δm = μΔx
Hence, Kinetic energy is:
ΔUkinetic = 1/2 (μΔx)vy2
For total kinetic energy of wave we have,
Ukinetic = 1/4(μA2ω2λ)
where A is the amplitude of the wave (in metres), ω is the angular frequency of the wave oscillator (in Hertz), λ is the wavelength (in metres).
- Potential Energy Component
In Oscillations, the potential energy stored in a spring with a linear restoring force is,
U = 1/2ksx2
where the equilibrium position is defined at x = 0 m.
The potential energy of the mass element is,
U = 1/2ksx2
= 1/2 Δmw2x2
= 1/4 (μA2ω2λ)
where A is the amplitude of the wave (in metres), ω is the angular frequency of the wave oscillator(in hertz), λ is the wavelength (in metres).
- Hence, the Total Wave Energy
Utotal = Upotential + Ukinetic
= 1/4(μA2ω2λ) + 1/4(μA2ω2λ)
Utotal = 1/2(μA2ω2λ)
where A is the amplitude of the wave (in metres), ω the angular frequency of the wave oscillator(in hertz), and λ the wavelength (in metres).
Wave energy has two components kinetic energy of wave particles and potential energy.
Wave energy, U = Upotential + Ukinetic = 1/4(μA2ω2λ) + 1/4(μA2ω2λ) = 1/2(μA2ω2λ)
where A is the amplitude of the wave (in meters), ω the angular frequency of the wave oscillator (in Hertz), and λ the wavelength (in meters).
Since, according to the Wave energy formula, the intensity of a wave is directly proportional to the square of the amplitude of the wave.
So, the relation can be written as:
I ∝ X2
Here I is the intensity and X is the amplitude.
To increase the intensity by a factor of 64 we need to increase the amplitude by a factor of (64)1/2 which is equal to 8.
Since, according to the Wave energy formula, the intensity of a wave is directly proportional to the square of the amplitude of the wave.
X2 ∝ I
Here I is the intensity and X is the amplitude.
To increase amplitude by a factor of 5 we need to increase the intensity by a factor of (5)2 which is equal to 25.