Two stones are launched from the top of a tall building. One stone is thrown in a direction 20.0 ∘ above the horizontal with a speed of 16.0 m/s ; the other is thrown in a direction 20.0 ∘ below the horizontal with the same speed.

Which stone spends more time in the air? (Neglet air resistance)

a. The stone thrown upward spends more time in the air.

b. The stone thrown downward spends more time in the air.

c. Both stones spend the same amount of time in the air.

A. The stone thrown upward spends more time in the air.

Explanation:

The stone thrown above the horizontal has an initial vertical speed, whose direction is opposed to gravity. It means that it decelerate first before accelerating in the direction of gravity. Where the stone thrown below the horizontal has an initial vertical speed in the direction of gravity, so there is no deceleration.

In consequence, the stone thrown upward spends more time in the air. Correct answer is option A.

the maxium height is 34m/s