You drop a 2.70 kg book to a friend who stands on the ground at distance D = 12.0 m below. Your friend's outstretched ha

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You drop a 2.70 kg book to a friend who stands on theground at distance D = 12.0 m below.Your friend's outstretched hands are atdistance d = 1.60 m above the ground(see the figure). (a) What is the speedof the book when it reaches herhands? (b) If we substituted a secondbook with twice the mass, what would its speed be when it reachesher hands? (c) If, instead, the bookwere thrown down with initial speed 6.20 m/s, what wouldbe the answer to (a)?