You throw a ball straight up at 25 m/s. How many seconds elapse before it is traveling downward at 13 m/s?
1 s
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To find the time it takes for the ball to reach a velocity of 13 m/s, we can set up an equation based on the laws of motion. Let's assume the upward velocity is positive and the downward velocity is negative.
The initial velocity is given as 25 m/s. The final velocity is -13 m/s. We need to find the time it takes for the ball to reach this velocity.
Using the equation of motion:
v = u + at
where:
v = final velocity
u = initial velocity
a = acceleration (in this case, due to gravity which is approximately -9.8 m/s²)
t = time
Rearranging the equation to solve for time:
t = (v - u) / a
Substituting the values into the equation:
t = (-13 - 25) / (-9.8)
t = -38 / (-9.8)
t ≈ 3.88 seconds
Therefore, it takes approximately 3.88 seconds for the ball to be traveling downward at 13 m/s.