Answer:
d) velocity-time graph is nonlinear
Explanation:
A straight line is seen in the velocity-time graph for uniform acceleration in rectilinear motion.
Answer:
You should face your fears sometimes, and get in front of a crowd do present your ideas. Not everyone is good at it, and many people get anxious when they have to speak in front of people but it’s best if you just do it and get it over with and maybe it won’t be as intimidating next time :)
Answer:
8.70 seconds.
Explanation:
1. Use the kinematic equation: v = u + at,
v = final velocity
u = initial velocity
a = acceleration
t = time.
Find variables and numbers:
v = ?
u = 20 m/s
a = -2.3 m²
v = 0 m/s
Rearrange values: t = (v - u) / a.
Plugging in the values: t = (0 - 20) / (-2.3) = 20 / 2.3
at a particular frequency and sound is produced.
This phenomenon is called
(1) diffraction (3) resonance
(2) refraction (4) the Doppler effect
Answer:
resonance
Explanation:
Resonance is when the frequency matches another objects natural frequency causing it to vibrate.
photon?
(1) 1.86 × 10^22 J (3) 4.14 × 10^−19 J
(2) 1.44 × 10^2 J (4) 3.18 × 10^−26 J
Taking into account the definition of photon, energy of a photon, wavelength, frecuency and propagation speed, the correct answer is the option (3): The energy of a photon with aa wavelength of 4.80×10⁻⁷ meter is 4.14×10⁻¹⁹ J.
You have to know that electromagnetic radiation carries energy, which can be absorbed or emitted. To explain the processes of emission and absorption, Plank and Einstein proposed that the energy of radiation is composed of indivisible units (quanta). In each elemental process only a quantum of light can be emitted or absorbed. Each of these quanta was called a "photon".
The exchanges of energy between matter and radiation take place not continuously, but by discrete and indivisible quantities or quanta of energy. The quantum of energy is proportional to the frequency of radiation.
The relationship between the amount of energy (E) transported by the photon and its frequency (f) is determined by the following expression, where the energy of a photon is obtained by multiplying Planck's constant h by the frequency f of electromagnetic radiation:
E=h×f
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
On the other side, frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).
Finally, the propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave disturbance propagates along its displacement.
The propagation speed relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f×λ
All electromagnetic waves propagate in a vacuum at a constant speed of 3×10⁸ m/s, the speed of light.
In this case, you know:
Replacing in the definition of energy of a photon:
E=h× (v÷λ)
E= 6.63×10⁻³⁴ Js× (3×10⁸ m/s ÷4.80×10⁻⁷ m)
Solving:
E= 4.14×10⁻¹⁹ J
Finally, the correct answer is the option (3): The energy of a photon with aa wavelength of 4.80×10⁻⁷ meter is 4.14×10⁻¹⁹ J.
Learn more about
definition of photon and energy of a photon:
wavelength, frecuency and propagation speed:
#SPJ5
1 velocity.
2 speed.
3 acceleration.
4 direction.
Answer : speed
Explanation :
Speed is defined as the distance travelled per unit time. It is a scalar quantity.
Velocity is displacement covered per unit time. It is a vector quantity. This means it have both magnitude as well as direction.
When captain told the passengers that the plane is flying at 450 miles per hour, then this shows the speed of plane. He is not talking about the direction in which the plane is flying.
So, this information describes the speed of plane.
Correct option is (2).