It is not enough to describe some objects by their location. We may also need to know its direction. For example, a wind blows a storm over your school. Where is that storm coming from? Where is it going? How can we describe a direction? The most common way is by using a compass. A compass is a device with a floating needle (Figure 2.1). The needle is a small magnet. The needle aligns itself with the Earth's magnetic field. The compass needle always points to magnetic north. If you have a compass and you find north. You can then know any other direction. See the directions, such as east, south, west, etc., on a compass rose. The Earth has two poles. It has a magnetic north pole. It also has a geographic north pole. These two poles are close to each other but not the exact same place.

How can we tell where east, west, and south are with a compass?

Oscar-winning actress Joan Fontaine died Sunday, her longtime friend Noel Beutel said Monday. She was 96. Fontaine died "very peacefully" in her sleep of natural causes, Beutel said. She was in her Carmel, California, home. She is survived by her older sister, actress Olivia de Havilland -- with whom she had not spoken for decades. Fontaine was born Joan de Beauvoir de Havilland in 1916 in Tokyo, Japan, where her British father was a patent lawyer and teacher. She and her sister moved to Saratoga, California, with their mother in 1919 when her parents separated. Fontaine was a teenager when she began her acting career as Joan Burfield in the 1935 film "No More Ladies." She later adopted the stage name Fontaine -- the name of her mother's second husband. She wrote in her 1978 autobiography, "No Bed of Roses," that her mother, who was an actress, began encouraging the rivalry with her older sister at an early age. The feud extended to their careers when both sisters were nominated for best actress Oscars in 1942. Fontaine, who was nominated for Alfred Hitchcock's "Suspicion," beat her sister Olivia de Havilland, who was nominated for "Hold Back the Dawn." De Havilland won the first of her two Oscars in 1947 when she was given the best actress award for "To Each His Own." De Havilland and Fontaine remain the only sisters who have best-actress Academy Awards. The long-standing feud with de Havilland was at such a peak during one Oscar winners' reunion in 1979 that they had to be seated on opposite ends of the stage. "I was shocked and saddened to learn of the passing of my sister, Joan Fontaine ... and I appreciate the many kind expressions of sympathy that we have received," a statement released by Olivia de Havilland to CNN said.

List 2 of the movies the Fontaine and De Havilland sisters won Oscars for?

If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force. Mass and weight are closely related. However, the weight of an object can change if the force of gravity changes. On Earth, the force of gravity is the same everywhere. So how does the force of gravity change? It doesnt if you stay on Earth. What if we travel to another planet or moon in our solar system? Look at the photo of astronaut Edwin E. Aldrin Jr. taken by fellow astronaut Neil Armstrong in the Figure. They were the first humans to walk on the moon. An astronaut weighs less on the moon than he would on Earth. This is because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. If the astronaut weighed 175 pounds on Earth, he would have weighed only 29 pounds on the moon. If his mass on Earth was 80 kg, what would his mass have been on the moon? [Figure 3]
Who were the first humans to walk on the moon?