Question

A stationary solid object weighing $3.5\text{kg}$ falls from a height of $2000\text{m}$ on a snow at $0^{\circ }\text{C}$. The object comes to rest immediately after collision. Then the amount of ice melted is
(Assume that all the energy of the ball is used in melting ice, latent heat of ice is $3.5\times 10{}^5\text{J/kg}$ and neglect air drag)

• A. $250\text{g}$
• B. $230\text{g}$
• C. $200\text{g}$
• D. $275\text{g}$

Answer 1

The correct option is C $200\text{g}$

Since initially the object is having only potential energy (PE). Therefore all the PE will be used in melting $m\text{kg}$ of ice.
PE = $mL$
$Mgh=mL$
$\Rightarrow 3.5\times 10\times 2000=m\times 3.5\times 10{}^5$
$m=0.2\text{kg}=200\text{g}$