Sorin hits a cricket ball straight up into the air. After 1.5s, the ball is falling straight down with a speed of 6.5 m/s. We want to find the initial vertical velocity of the ball. We can ignore air resistance. Which kinematic formula would be most useful to solve for the target unknown?

Step-by-step explanation:

We have, Sorin hits a cricket ball straight up into the air. After 1.5 s, the ball is falling straight down with a speed of 6.5 m/s.

We want to find the initial vertical velocity of the ball.

The relation between initial speed, final speed, acceleration and time is given by using first equation of kinematics. Let v₀ is the initial speed. So,

Here, v = -6.5 m/s, t = 1.5 s and a = -g

So, the initial velocity of the ball is 8.2 m/s and the formula used is (1).

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