Matt tosses a set of keys straight up to Sanjit, who catches them from a window 1.1 s later at a height of 14 m above the point of release. T/I (a) Determine the initial velocity of the keys. [ans: 18 m/s [up]] (b) Determine the velocity of the keys when they were caught. [ans: 7.3 m/s [up]]

The answer is  a.first and third quarters 

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other