Answer:
mass of one atom is measured in the unit of 1 amu
Explanation:
As we know that the mass of one atom is very small and it is of order of 
here we know that 1 amu is defined as 1/12 part of mass of 1 atom of C-12 isotope
so here we will have

so here we can say that mass of one atom is measured in the unit of 1 amu
Answer:
29 counts per minute (29 cpm)
Explanation:
The half-life of a radioactive isotope is the time needed for the activity of the sample to halve.The half-life of Francium-223 is exactly 22 minutes: this means that its activity after 22 minutes becomes exactly half of its initial value. Since the initial activity of this sample of francium-223 was 58 cpm, the activity after 22 minutes will be

An atom is the smallest unit of matter. It can't be broken. It consist of dense nuleus surrounded by negatively charged electrons.
Answer:
a. The station is rotating at 
b. the rotation needed is 
Explanation:
We know that the centripetal acceleration is

where
is the rotational speed and r is the radius. As the centripetal acceleration is feel like an centrifugal acceleration in the rotating frame of reference (be careful, as the rotating frame of reference is <u>NOT INERTIAL,</u> the centrifugal force is a fictitious force, the real force is the centripetal).
<h3>a. </h3>
The rotational speed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


<h3>b. </h3>
The rotational speed needed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


Answer:
<h2>The answer is planetary motion</h2>
Explanation:
According to Johannes Kepler, the laws governing planetary motion
states that:
1. The orbit of a planet is an ellipse with the Sun at one of the two foci.
2. A line segment joining a planet and the Sun sweeps out equal areas
during equal intervals of time.
3. The square of a planet's orbital period is proportional to the cube of the semi-major of its orbit.
Johannes Kepler was a German astronomer, mathematician, and astrologer
Born: 27 December 1571, Weil der Stadt, Germany
Died: 15 November 1630