MCQ
A body falls freely under gravity. Its speed is $v$ when it has lost an amount $U$ of the gravitational energy. Then its mass is
- A$\frac{{Ug}}{{{v^2}}}$
- B$\frac{{{U^2}}}{g}$
- ✓$\frac{{2u}}{{{v^2}}}$
- D$2\,Ug{v^2}$
✓
Answer
Correct option: C.
$\frac{{2u}}{{{v^2}}}$
c
(c) $U =$ Loss in gravitational energy = gain in $K.E.$
(c) $U =$ Loss in gravitational energy = gain in $K.E.$
So, $U = \frac{1}{2}m{v^2}\, \Rightarrow \,m = \frac{{2U}}{{{v^2}}}$
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