Children, even those that are vaccinated, may develop rotavirus disease more than once. That is because neither natural infection with rotavirus nor rotavirus vaccination provides full immunity (protection) from future infections. Usually a personâs first infection with rotavirus causes the most severe symptoms.
Because molecules move quicker at higher temperature, causing them to collides more. Since they collides more, reaction occurs to be a lot faster to. And that's why things dissolve quicker in hot water than in room temperature water.
Caster sugar which is made of fine particles will dissolve quickly, but bigger sugar particles will take longer. Solids dissolve faster in hot water as in hot water the water molecules are moving faster, so bump into the solid more often which increases the rate of reaction.