Answer:
substance A as well as substance B will be at liquid state at 115 degree Celsius.
Both substance A and B will posses kinetic energy because they are now both liquid at 115 degree Celsius.
Explanation
Solid substance A
The melting point of Solid substance A is 100 degrees Celsius. once the temperature increases more than 100 degrees Celsius it becomes liquid, So at 115 degrees Celsius, the substance A is liquid.state.
As a result in increase of thermal energy the substance is subjected to, the particles becomes loose and will become free to the extent that they can be slidding over each other.
Liquid substance B
The freezing point of substance B is 110 degrees Celsius. As the temperature increases to 115 degrees Celsius, substance B will still maintain it's liquid state, there is no change of state at that temperature.
At that temperature the particles are free as it is close to themselves and can also slide over each other.
NOTE:
The melting point of a substance can be defined as the temperature whereby there is change of state from solid to liquid.
The Freezing point is the temperature at which a liquid becomes a solid.
