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The short answer (and the long one for that matter) is physical properties of chemicals. If you are being marked by a machine, likely the answer is going to be physical properties.
The answer would be letter choice B
Answer:
The radius of a chamber is 2.36 meters.
Explanation:
Given that,
The outer wall moves at a speed of 2.72 m/s.
Mass of the person, m = 75.1 kg
The person feels a force of 235 N force pressing against his back. The force acting on the person is centripetal force. It is given by the below formula :

r is the radius of a chamber


r = 2.36 meters
So, the radius of a chamber is 2.36 meters. Hence, this is the required solution.
Answer:
If a body is electrically neutral it means it has no net charge.
Explanation:
Because it has the same number if protons as it does electron , which are opposite charges that offset eachother.