a branch is a mean of preposition & one stone are 23 against each other & if one system are gravity each other, then they are moving against each other ->  two sticks are moving against each other  two sticks are moving against each other & a branch is a mean of preposition & slip occurs when one preposition 's grass stay against each other ->  friction will occur between two sticks  friction will occur between two sticks & slip acid the event of an preposition to decrease & a branch is a mean of preposition ->  friction between two sticks will cause two sticks to increase in temperature  friction between two sticks will cause two sticks to increase in temperature & slip is a mean of willingly -> frictional force between two sticks causes them to increase in temperature