Question

A ball is launched upward with an initial velocity of 20 m/s. What is the speed and direction (hence velocity) ofthe ball 2 seconds into its flight? For this problem, round g=-9.8 m/s2 to g=-10 m/s2 for simplicity, and assumeno air resistance of any kind is present.

Answer 1

Answer:

velocity = 0 m/s

Explanation:

The velocity after t seconds can be calculated as:

$v=v_0+at$

Where v0 is the initial velocity and a is the acceleration. In this case, the acceleration is gravity, so a = g = -10m/s²

Then, replacing v0 by 20m/s and a by -10m/s², we get:

$v=20-10t$

Therefore, the velocity after 2 seconds will be equal to:

$\begin{gathered} v=20-10(2) \\ v=20-20 \\ v=0\text{ m/s} \end{gathered}$

Since the velocity is 0 m/s, there isn't a direction.

So, the answer is:

velocity = 0 m/s