B is true because plants can only use nitrogen in the form of nitrates, no other living thing needs nitrogen therefore the percentage of nitrogen in the atmosphere is 79%
A canyon is a deep ravine between pairs of escarpments or cliffs and is the most often carved landscape by the erosive activity of a river over geologic timescales. A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains, the Alps, the Himalayas or the Andes.
a small cavity or space in tissue, especially in nervous tissue as the result of disease.
Answer:
fundamental frequency in helium = 729.8 Hz
Explanation:
Fundamental frequency of an ope tube/pipe = v/2L
where v is velocity of sound in air = 340 m/s; λ is wave length of wave = 2L ; L is length of the pipe
To find the length of the pipe,
frequency = velocity of sound / 2L
272 = 340 / 2 L
L = 0.625 m
If the pipe is filled with helium at the same temperature, the velocity of sound will change as well as the frequency of note produced since velocity is directly proportional to frequency of sound.
Also, the velocity of sound is inversely proportional to square root of molar mass of gas; v ∝ 1/√m
v₁/v₂ = √m₂/m₁
v₁ = velocity of sound in air, v₂ = velocity of sound in helium, m₁ = molar mass of air, m₂ = molar mass of helium
340 / v = √4 / 28.8
v₂ = 340 / 0. 3727
v₂ = 912.26 m /s
fundamental frequency in helium = v₂ / 2L
fundamental frequency in helium = 912.26 / (2 x 0.625)
fundamental frequency in helium = 729.8 Hz
Answer
If the temperature is increased , the number of collision per second increases.
Explanation
Temperature is proportional to the average kinetic energy of a sample of a gas according to the equation PV=n R T. An increased in temperature , increases the kinetic energy of the gas particles which in turn rises the velocity of the gas particles hitting the walls of the container. The more the number of particles the higher the collision rate and greater the pressure as long as the volume of container and the temperature are constant.
