Question

What is the value of 1 fermi in m?
A) \[{10^{ - 3}}\]
B) \[{10^{ - 6}}\]
C) \[{10^{15}}\]
D) \[{10^{ - 15}}\]

Answer 1

Hint: Length is a measure of the distance a body travels or the size of the object. We will use the conversion of 1 meter to fermi to determine the value of 1 fermi in metres.

Complete step by step answer:
The value of fermi is also known sometimes as a femtometer.
We know that the relation between 1 meter and 1 femtometer is given as
$1\,m = {10^{15}}\,fm$
Since a fermi is equal to the length of a femtometer, there are ${10^{15}}$ femtometers in 1 meter. This relation can be inverted and we can write that the number of metres in 1 fermi will be
$1\,fm = {10^{ - 15}}m$
Hence the value of 1 fermi in metres is \[{10^{ - 15}}\] metres which correspond to option (D).
Additional information: A fermi is a small unit of measurement that measures length. It is another name for a femtometer which is one- quadrillionth of a meter. The unit of femtometers is used in many fields, such as nuclear physics where the typical distance between particles is of the order of a few fermis. For example, the charge radius of a proton is approximately \[0.831\] fermi while the radius of a gold nucleus is approximately \[8.45\] fermi.
 The relation of the meter with different units is given as
1 centimetre (cm) = 0.01 m
1 millimetre (mm) = 0.001 m
1 micrometre (μm) = ${10^{ - 6}}$m
1 nanometre (nm) = ${10^{ - 9}}\,$m

Note: To solve such questions, we must memorize the relations between different units of length. The fermi is just another word for a femtometer of length and we should realize to directly utilize the relation with a meter and a femtometer to convert the length in fermi to metres.