The center of mass is given with this formula:

Velocity is:

So, for the velocity of the center of mass we have:

In our case it is:
Answer: A force must cause a displacement in order for work to be done. A book falls off a table and free falls to the ground. Yes. This is an example of work.
Explanation:
1,000 grams = 1 kilogram
20 grams = 0.02 kilogram
Kinetic energy = (1/2) (mass) x (speed)²
(1/2) (0.02) x (15)² =
(0.01) x (225) = 2.25 joules
<h2>Greetings!</h2>
To find speed, you need to remember the formula:
Speed = distance ÷ time
So plug the given values in:
500 ÷ 30 = 16.66
<h3>So the speed is 16.66m/s (metres per second)</h3>
<h2>Hope this helps!</h2>