A ball is thrown vertically upwards from the roof of a building with an initial velocity of 30 m / s. If it stops in the air 220 m above the ground, what is the height of the building?

175 m

Explanation:

Given:

y = 220 m

v₀ = 30 m/s

v = 0 m/s

a = -10 m/s²

Find: y₀

v² = v₀² + 2a (y − y₀)

(0 m/s)² = (30 m/s)² + 2 (-10 m/s²) (220 m − y₀)

y₀ = 175 m

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

object 2 because all the other ones are wrong