'J A student on a skateboard, with a combined mass of 78,2 kg, is moving east at
1,60 m. s 1. As he goes by, the student skilfully scoops his 6,4 kg backpack from the
bench where he had left it. What will be the velocity of the student immediately
after the pickup?​

v = 1.48 m / s

Explanation:

This is an exercise in conserving the moment. Let's define a reference system made up of the student, the scooter and the collected mass. For this system the forces during the collection are internal and element and conserves

initial interim. Before picking up the merchandise

       p₀ = M v₀

final instant. After picking up the object

       p_f = (M + m ') v

how the moment was created

        p₀ = p_f

       M v₀ = (M + m) v

let's calculate

       v =  vo

       v = 78.2 / (6.4 +78.2) 1.60

       v = 1.48 m / s

d. air pressure decreases as altitude increases.

d) physical means can be used to separate the components of air.