Answer:
102 dB
Explanation:
Intensity level is given by:




The correct answer is A. Electromagnetic waves can transfer energy without a medium. Heat can be transferred through a vacuum only via radiation. Infrared waves are electromagnetic waves that does not require a medium to travel. Heat is transferred in a vacuum in the form of infrared waves.
Answer: The partial pressure of
if the total pressure of the mixture is 3.9 atm is 0.975 atm
Explanation:
According to Raoult's law, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component multiplied by the vapor pressure of that component in the pure state.

where, x = mole fraction of nitrogen in solution = 0.25
= partial pressure of nitrogen = ?
= Total pressure = 3.9 atm
Putting in the values :

The partial pressure of
is 0.975 atm
They can't hear an echo in small room because in it the sound can't be reflected back. For an echo of a sound to be heard,the minimum distance between the source of sound and the walls of the roomshould be 17.2 m. Obviously,in asmall room echoes cannot beheard.
The distance from the base of the building the rock will land is 26.4 m
<h3>Data obtained from the question </h3>
- Horizontal velocity (u) = 20 m/s
- Height (h) = 8.50 m
- Distance (s) =?
<h3>Determination of the time to reach the ground </h3>
- Height (h) = 8.50 m
- Acceleration due to gravity (g) = 9.8 m/s²
- Time (t) =?
h = ½gt²
8.5 = ½ × 9.8 × t²
8.5 = 4.9 × t²
Divide both side by 4.9
t² = 8.5 / 4.9
Take the square root of both side
t = √(8.5 / 4.9)
t = 1.32 s
<h3>How to determine the distance </h3>
- Horizontal velocity (u) = 20 m/s
- Time (t) = 1.32 s
- Distance (s) =?
s = ut
s = 20 × 1.32
s = 26.4 m
Learn more about motion under gravity:
brainly.com/question/22719691