The Earth itself is a source of terrestrial radiation. Radioactive materials including uranium, thorium, and radium exist naturally in soil and rock. Essentially all air contains radon<span> , which is responsible for most of the dose that Americans receive each year from natural background sources.</span>
Using the metric units kilometer (km) and meter (m), as seen in the picture of the ladder method example. So, the answer would be 14km = 14000m
Answer:

Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by
--------eqn 1
The angle through which the first minima is diffracted is given by
---------eqn 2
As
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3


This would be an example of active immunity
Answer:
Explanation:
mass, m = 1.25 kg
angular speed, ω = 235 rad/s
The moment of inertia of the cylinder is given by
I = 1/2 mr²
(a) the kinetic energy of rotation is given by
K = 1/2 Iω²
K = 1/4 mr²ω²
where, m is the mass of cylinder and r be the radius of cylinder
K = 0.25 x 1.25 x 0.32 x 0.32 x 235 x 235
K = 1767.2 J
(b) the kinetic energy of rotation is given by
K = 1/2 Iω²
K = 1/4 mr²ω²
where, m is the mass of cylinder and r be the radius of cylinder
K = 0.25 x 1.25 x 0.7 x 0.7 x 235 x 235
K = 8456.33 J