Answer:
What is a Pure Substance?
Explanation:
It is something which cannot be divided into parts by physical means, as it's all made up of the same thing. Pure substances are either elements or compounds. Elements can NOT be separated into other types of matter (physically or chemically).
Explanation:
It is given that,
Mass of the woman, m₁ = 52 kg
Angular velocity, 
Mass of disk, m₂ = 118 kg
Radius of the disk, r = 3.9 m
The moment of inertia of woman which is standing at the rim of a large disk is :


I₁ = 790.92 kg-m²
The moment of inertia of of the disk about an axis through its center is given by :


I₂ =897.39 kg-m²
Total moment of inertia of the system is given by :


I = 1688.31 kg-m²
The angular momentum of the system is :



So, the total angular momentum of the system is 4980.5 kg-m²/s. Hence, this is the required solution.
If the heart is beating at 76. 0 beats per minute, the Frequency of heart's oscillations in hertz is 1.25 Hertz.
The Frequency is defined as the number of oscillations completed in 1s.
Our heart beats continuously giving rise to the frequency of the heart.
Measuring frequency would be possible if we measure the time in seconds.
75 beats per minute means that 75 beats occur in 60s.
Frequency = Number of beats / Total time taken
Frequency = 75 / 60
Frequency = 1.25 Hz
Hence, number of beats per second is 1.25 Beats.
Beats per second or Cycles per second is same as the frequency of oscillation called as Hertz (Hz)
Hence, frequency of the heart oscillation is 1.25 Hertz (Hz).
Learn more about Frequency here, brainly.com/question/14316711
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