Question
Two objects having equal masses are moving with uniform velocities of $2m/s$ and $6m/s$ respectively. Calculate the ratio of their kinetic energies.
✓
Answer
Let masses of the two objects be $m.$
$\text{v}_1 = 2\text{m}/\text{s}$
$\text{v}_2 = 6\text{m}/\text{s}$
$\text{KE}_1=\frac{1}{2}\text{m}\times\text{v}_1^2$
$=\frac{1}{2}\text{m}\times2^2$
$\text{KE}_2=\frac{1}{2}\text{m}\times\text{v}_2^2$
$=\frac{1}{2}\text{m}\times6^2$
$\text{Ratio}=\frac{\text{KE}_1}{\text{KE}_2}$
$=\frac{2^2}{6^2}=\frac{4}{36}=\frac{1}{9}$
$\text{v}_1 = 2\text{m}/\text{s}$
$\text{v}_2 = 6\text{m}/\text{s}$
$\text{KE}_1=\frac{1}{2}\text{m}\times\text{v}_1^2$
$=\frac{1}{2}\text{m}\times2^2$
$\text{KE}_2=\frac{1}{2}\text{m}\times\text{v}_2^2$
$=\frac{1}{2}\text{m}\times6^2$
$\text{Ratio}=\frac{\text{KE}_1}{\text{KE}_2}$
$=\frac{2^2}{6^2}=\frac{4}{36}=\frac{1}{9}$
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