Question

A meter stick flies by an apparent length of 60 cm. What is its velocity (in m/s)?

Answer 1

this sounds like a relativity question dealing with contraction of space

Answer 2

\[l=l _{0}\sqrt{1-\frac{ v ^{2} }{ c ^{2} }}\]\[\frac{ 60 }{ 100}=0.6=\sqrt{1-\frac{ v ^{2} }{ c ^{2} }}\]
as,
\[\frac{ l }{ l _{0} }=\sqrt{1-\frac{ v ^{2} }{ c^{2} }}\]
therefore,
squaring both the side,
\[0.36=1-\frac{ v ^{2} }{ c^{2} }\]
\[\frac{ v ^{2} }{ c ^{2} }=0.64\]
taking square root,\[v=0.8c\]