Question

if a ball is accelerated downward at 9.8m/s, by how many meters per second does the object's velocity change every second?

Answer 1

The velocity will change (increase) by 9.8 m/s every second.

Why?

Since the ball is accelerated downward at $9.8\frac{m}{s^{2} }$ we can see that the ball is on "free fall". It means that the wall was dropped with no initial speed.

Now, if we want to know by how many meters per second does the object's velocity change every second, we need to understand the units of the acceleration. Let's write the equation of acceleration for better understanding.

$Acceleration=\frac{ChangeInVelocity(\frac{m}{s})}{time(s)}\\\\Acceleration=\frac{\frac{m}{s} }{s}=\frac{m}{s^{2} }$

So, from the equation we can see that the acceleration is changing the velocity every second.

Hence, if an object has the given acceleration (acceleration due to gravity, 9.8m/s2), it means that its speed will change (increase) by 9.8m/s every second.

Have a nice day!