Answer:
Earth's atmosphere was largely made up of nitrogen and carbon dioxide gases. After photosynthesizing organisms multiplied on Earth's surface and in the oceans, much of the carbon dioxide was replaced with oxygen.
Idk if this helps but plz mark brainliest if it does
Explanation:
The magnetic needle of a compass lines up with Earth's magnetic poles.
Answer:

Explanation:
F = Force on the sled = 63 N
m = Mass of sled = 28.7 kg
= Coefficient of kinetic friction = 0.169
g = Acceleration due to gravity = 
The force balance of the system is given by

The acceleration of the sled is
.
Activation Energy is the amount of energy needed to get a reaction started.