A 100 N force Gad a soccer ball flying through the air at 20m/s^2

What is the mass of the soccer ball

We know that F=m·a. For this particular problem, since 'm' is what we need to find, we can divide each side of the formula by 'm', and then it says m=F/a. Much more convenient.

Now all we have to do is write "100N" where it says "F", and write "20m/s²" where it says 'a'. Then the formula is m = (100N/20m/s²).

When you massage that out, it finally says "m=5 kg".

But I gotta tell ya, that's no soccer ball. On Earth, anything with 5 kg of mass weighs a hair more than 11 pounds! You wouldn't want to play a game where you had to kick that thing or hit it with your head. 5 kg is more like a bowling ball.