Question

question 25 of 25
you throw a baseball straight up into the air with a speed of 24.5 m/s. how long does it take the baseball to reach its highest point?
a. 0.4 s
b. 3.2 s
c. 1.1 s
d. 2.5 s

Explanation:

Step1: Identify the kinematic - equation

Use the equation $v = v_0+at$. At the highest - point, the final velocity $v = 0$. The initial velocity $v_0 = 24.5$ m/s and the acceleration $a=-g=- 9.8$ m/s² (negative because it acts in the opposite direction of motion).

Step2: Rearrange the equation for time

$v = v_0+at$ can be rearranged to $t=\frac{v - v_0}{a}$. Substitute $v = 0$, $v_0 = 24.5$ m/s and $a=-9.8$ m/s² into the formula.
$t=\frac{0 - 24.5}{-9.8}$

Step3: Calculate the time

$t=\frac{-24.5}{-9.8}=2.5$ s

Answer:

D. 2.5 s