Question

A ball is thrown with a velocity of 3.0 m/s at an angle of 30° above horizontal. Its vertical velocity is zero when: The ball is at its maximum height. Just before the ball hits the ground. When the ball changes direction. Never during the ball's flight.

Answer 1

Answer:

The ball is at its maximum height.

Explanation:

As we know that when ball is thrown at some angle with the horizontal then the component of its velocity is given as

$v_x = vcos\theta$

$v_y = vsin\theta$

now here vertical velocity is the velocity in y direction

so it is given as

$v_y = 3.0 sin30 = 1.5 m/s$

now as the velocity of ball in vertical direction becomes zero

then in that case

$v_f - v_i = at$

$0 - 1.5 = (-9.8)t$

$t = 0.15 s$

since at this position the vertical component of the velocity is zero

so this is the position of ball when its height is maximum