A man on top of a tall building 60m high projects a body vertically upwards with an initial velocity of 20m/s (1) find the maximum height above the ground reached by the body.

(2) the velocity with which the body hits the ground.
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1) 65 m

2) 40 m/s downward

Explanation:

Using for both questions the kinematic equation

v² = u² + 2as

and ignoring air resistance.

1) h = 60 + √(20²/(2(9.8))) = 64.51753...

2) v = √(20² + 2(9.8)(60)) = 39.69886...

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .