ANSWER
625 m/s
EXPLANATION
Given:
• The frequency of the sound wave, f = 250 Hz
,
• The wavelength, λ = 2.5 m
Find:
• The speed of the wave, v
The speed of a wave of wavelength λ and frequency f is given by,
Substitute the known values and solve,
Hence, the speed of the wave is 625 m/s.
The characteristics of electromagnetic waves typically represent as follows:
- There are changes in the electric and magnetic fields simultaneously so that both fields have maximum and minimum values at the same time and place.
- The direction of the electric field and the magnetic field are perpendicular to each other. The direction of both is perpendicular to the direction of the wave propagation.
- The shape of electromagnetic waves is transverse waves.
- It has general wave characteristics like polarization, reflection, refraction, interference, and diffraction.
- The amount of the electric field (E) is directly proportional to the magnitude of the magnetic field, with the relationship E = cB.
- The universal constant of the velocity of electromagnetic waves in a vacuum is
- The speed at which electromagnetic waves propagate depends merely on the electrical and magnetic properties of the medium that it travels on.
- Because electromagnetic waves do not contain an electric charge, they do not experience any possible deviation in the electric or magnetic fields.
<h3>Further explanation</h3>
- Two physicists who contributed significantly to developing the concept of electromagnetic waves are Faraday and Maxwell around 1831-1864.
- From the observations, Faraday suggested that changes in the magnetic field cause an electric charge to flow in the loop of wire, contributing in the emergence of an electric field.
- Maxwell proposed a reverse process, which is a change in the electric field will generate a magnetic field.
- As follows, according to Faraday's Law, changes in sinusoidal magnetic fields generate electric fields which also change sinusoidally.
- Meantime, according to Maxwell's Hypothesis, changes in sinusoidal electric fields generate magnetic fields which also change sinusoidally.
- Furthermore, there is a process of combining electric and magnetic fields that propagate in all directions called electromagnetic waves.
<h3>Learn more </h3>
- About vector components brainly.com/question/1600633
- Determine the shortest wavelength in electron transition brainly.com/question/4986277
- Particle's speed and direction of motion brainly.com/question/2814900
Keywords: the characteristics, electromagnetic waves, transverse, vacuum, electric fields, magnetic, perpendicular, propagation, Maxwell, Faraday, the speed, polarization, reflection, refraction, interference, and diffraction
Answer:
The kinetic energy of the phone would increase. The gravitational potential energy of the phone would decrease.
Explanation:
The kinetic energy 
of an object is proportional to the square of the speed of that object. If air resistance is negligible, the phone would accelerate under gravitational pull and speed up. Hence, the kinetic energy of the phone would increase.
The gravitational field near the surface of the earth is approximately constant. Hence, the gravitational potential energy 
of the phone would be proportional to its height. As the phone approaches the ground, the height of the phone becomes lower and the gravitational potential energy of the phone would decrease.
Explanation:
Force is applied to lift a body against the force of gravity. Example: If an object is lifted to a certain height (h)
Answer:
v = 15.65 m/s
Explanation:
We use conservation of mechanical energy between initial (i) and final (f) states:
Pi + KEi = Pf + KEf
At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.
Pi = m g h = 600 J
and the KEi = 0 J (no velocity)
Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:
m = 600 J / (g 12.5) = 4.9 kg
Using conservation of mechanical energy, the final state is:
Pf + KEf = 600 J
with Pf = 0 (just touching the ground)
KEf= 1/2 4.9 (v^2)
and we solve for the velocity:
600 J = 0 + 1/2 4.9 (v^2)
v^2 = 600 * 2 / 4.9 = 244.9
v = 15.65 m/s
