Question

a ball is thrown up in the air with an initial velocity of 60 m/s. what is the balls velocity after 2 seconds? (use g = 10m/s²)
0 m/s
20 m/s traveling upward
20 m/s traveling downward
40 m/s traveling upward

Explanation:

Step1: Identify the kinematic - equation

The kinematic equation for velocity is $v = v_0+at$, where $v$ is the final velocity, $v_0$ is the initial velocity, $a$ is the acceleration, and $t$ is the time. In the case of an object in free - fall near the Earth's surface, the acceleration $a=-g$ (negative because it acts in the opposite direction of the initial upward motion). Here, $v_0 = 60\ m/s$, $g = 10\ m/s^2$, and $t = 2\ s$.

Step2: Substitute the values into the equation

$v=v_0 - gt$. Substituting $v_0 = 60\ m/s$, $g = 10\ m/s^2$, and $t = 2\ s$ into the equation, we get $v=60-10\times2$.

Step3: Calculate the final velocity

$v=60 - 20=40\ m/s$. Since the result is positive, the direction of the velocity is upward.

Answer:

D. 40 m/s traveling upward