Tag: the essence of change

A block of ice falls from certain height and completely melts. If only 3/4th of the energy is absorbed by the block the height of fall should be

A block of ice at 0 C whose mass is initially 50.0 kg slides along a horizontal surface starting at a speed of 5.38 m/s and finally coming of ice melted as a result of the friction between the block and the surface will be

An ice block is falling from a height. If $75\%$ of the block melts then $h = (g = 10\ ms^{-2})$.

A block of mass 500Kg has dimension $10 \times 5 \times 2m$. It is placed on a table with the largest surface in contract. The work that must be done to turn it an place it so that the smallest surface is in contact with the table  

A lead ball moving with velocity v strikes a wall and stops. I 50% of its energy is converted into heat, then what will b the increase in temperature? (Specific heat of lead is s)

In an energy recycling process, $x _ { g }$ of steam at $100 ^ { \circ } C$ becomes water at $100 ^ { \circ } \mathrm { C }$ which converts $\mathrm { Yg }$ of ice at $0 ^ { \circ } \mathrm { C }$ into water at $100 ^ { \circ } \mathrm { C }$ . The ratio XY will be

$4180 J$ of work raises the temperature of $1$ litre water through:-

The work done on the particle of mass m by a force $ \overrightarrow { F } =K\left[ \frac { X }{ \left( X^ 2+y^ 2 \right)^{1/2}  } \hat { i } +\frac { y }{ \left( X^ 2+y^ 2 \right)^{1/2}   } \hat { j }  \right]  $ (k being a constant of appropriate simensions), when the particle is taken from the point (a,0) to the point (0,a) along a circular path of radius a about the origin in the X-y plane 

The maximum amount of work that can be done by extracting $1J$ of energy from a body at $127^oC$ with an environment at $27^oC$?

Which of the following energy conversions take place in a torch?