Answer: 4 x 106
That’s how you write forty million in scientific notation.
The force applied to the cannonball and cannon is equal. The explosion inside the cannon will generate a pressure which will turn into a force on both cannonball and cannon. The cannon being heavier and fixed to the ground will move a bit, but the cannonball will be thrown away, fired.
Your answers are correct. You have to read the plaques in the virtual lab to find the answers. So it shows you read them.
1. billion
2. modern
3. Organism
4. Heights
5. clams
6. flowery