In this second video giving an overview of World War II, we see Germany and the Axis powers only continue to gain momentum in 1940.

In 1941, the Axis gains further momentum with control of most of Continential Europe. Hitler decides to break pact and invade Stalin's Soviet Union. United States enters World War II after Japanese attack on Pearl Harbor.

In 1942 we see the Axis get pushed back in North Africa and get bogged down in the Soviet Union. The tide of war turns in favor of the Allies.

In 1943, the tide really turns in favor of the Allies in World War II. They are able to push the Axis out of N.Africa and force a surrender from Italy (along with Mussolini being deposed). The Soviets are able to start pushing the Axis out of the Soviet Union.

As we go into 1944, we see the allies land at Normandy, liberate France and face Germany in their last major counteroffensive at the Battle of the Bulge. On the Eastern Front, the Soviets end Siege of Leningrad and begin to push through Poland and Romania. In the south, Allies land in southern France and take Rome.

1945 marks the end of World War II. V-E Day (Victory in Europe Day) is May 8th 1945. War doesn't end in the Pacific until August of 1945 with the atomic bombing of Hiroshima and Nagasaki.

ATP synthase and its role in mitochondria during respiration and chloroplasts during photosynthesis.

A rational agent considers both accounting profit and economic profit. In this video, see an example highlighting the difference between accounting profit and economic profit from a business and a discussion of explicit and implicit costs of operating a business.

The simulation Sal mentions in the video can be found directly following this video in the lesson.

How and why a central bank would build foreign currency reserves. Created by Sal Khan.

Using the signal transduction pathway for the cholera toxin to understand activation and inhibition.

Exploring the actual weightings for the CPI-U basket of goods. Created by Sal Khan.

In this video we explore how to derive the demand for a factor of production based on how productive that factor is and how much additional revenue that factor brings in. Created by Sal Khan.

Explore the mechanics of adjustable rate mortgages (ARM) in this video, including how they work and in what situation an ARM might be advantageous and when it might work against you.

We've learned about demand for a good or service, but aggregate demand is different: its the demand for everything bought in an economy. In this video, we discuss how aggregate demand (AD) is different from demand and why aggregate demand is downward sloping. Created by Sal Khan.

Figuring how long it takes an A380 to take off given a constant acceleration. Created by Sal Khan.

Allele frequencies in populations and how they differ from genotype frequencies. Created by Sal Khan.

In 1944, the Americans (and Allies) make even more progress in the Pacific. By the end of the year, they have taken positions that put them within bombing range of Japan.