John is a wrestler. He applies oil on his body before every wrestling match. Why do wrestlers generally apply oil to their body while wrestling?

Once the spaceship is moving in space it does not need propelling. Why it is so?

Rahul was walking down a muddy path. He was slipping while walking. His father advised him to spread some sand and gravel on the sand. Why do we spread sand and gravel on mud during rains?

What is the greatest challenge to spaceships while moving through the atmosphere (air)?

Why does a matchstick not get ignited when strike against a smooth surface?

Why do meteors burn on entering the atmosphere?

Sam and his father was on fishing trip on a motorboat. After finishing fishing, they returned to the shore. When the boat was approaching the shore, Sam's father switched off the motor of the boat. Why is the motor of a motorboat switched off much ahead of approaching the shore?

Earth is moving round the sun without any slowing down. Give the reason behind it by considering the force of friction.