Question

sand kept in sun for half an hour

Answer 1

Sand takes a short time to get warmed as well as get cooled as its specific heat capacity is low.

therefore if sand is kept under the sun for an hour it becomes hot .

Answer 2

Sand kept in sun for half an hour the sand will become hot and it will help the air to get worm and rise up into the atmosphere and again it will come which is cold air and make soil cool. This process is also known as the sea and land bridge.

... Hope you got it...