Answer:
D. Frequency
Explanation:
The energy of an electromagnetic wave is proportional to frequency, mathematically it is expressed as;
E ∝ f
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
The equation above can also be expanded to;
where;
c is speed of light = 3 x 10⁸ m/s
λ is the wavelength of the electromagnetic wave
Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.
Therefore, the correct option for direct proportionality is FREQUENCY
Answer:
d. The large pot of water and small cup of water have the same temperature, but the large pot of water has higher thermal energy.
Explanation:
Temperature is a measure of the average kinetic energy of individual molecules. While internal energy refers to the total kinetic energy of the molecules within the object. Since in this case we have the same amount of average kinetic energy, then the large pot of water and small cup of water have the same temperature. While the large pot of water has higher thermal energy, since has more water particles than the small cup.
Answer:
B. 7.5 m/s^2
Explanation:
To find acceleration you need to subtract the final velocity by the starting velocity then divide that by the time
a= v-v/t
a= 60-0/8
a= 60/8
a=7.5 m/s^2
Answer:
When it's closest to the sun.
Explanation:
The force of gravity acting on a planet is equal to its mass times its centripetal acceleration.
Fg = m v^2 / r
The force of gravity is defined by Newton's law of universal gravitation as:
Fg = mMG / r^2
Therefore:
mMG / r^2 = m v^2 / r
MG / r = v^2
v increases as r decreases. So the planet is moving fastest when it's closest to the sun, also known as the <em>perihelion</em>.
Answer:
required distance is 233.35 m
Explanation:
Given the data in the question;
Sound intensity 
= 1.62 × 10⁻⁶ W/m²
distance r = 165 m
at what distance from the explosion is the sound intensity half this value?
we know that;
Sound intensity is proportional to 1/(distance)²
i.e
∝ 1/r²
Now, let r² be the distance where sound intensity is half, i.e ₂ = ₁/2
Hence,
₂/₁ = r₁²/r₂²
1/2 = (165)²/ r₂²
r₂² = 2 × (165)²
r₂² = 2 × 27225
r₂² = 54450
r₂ = √54450
r₂ = 233.35 m
Therefore, required distance is 233.35 m
