QUES: 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]
Do you have any questions?
MY QUESTION: Who were the first humans to walk on the moon?

QUES: (CNN) -- As Iranian President Mahmoud Ahmadinejad visited the U.N. General Assembly in New York last month, the spotlight was once again on Iran. And true to form, the Iranian president made his fair share of provocative statements for the Western media. But while Ahmadinejad's mercurial rants captured our media's attention, back in Iran a coordinated strategy against the women's movement continued. On the eve of Ahmadinejad's arrival to New York, Shiva Nazar Ahari, a prominent young female defender of human rights, received a heavy sentence of six years in prison on charges including the vague crime of "waging war against God" -- a convenient catch-all offense for anyone who criticizes the regime and its human rights record. There's no denying it -- Iran's women have had a bad year. Nazar Ahari joins a steadily increasing number of other women's rights activists who are in prison for no greater crime than their attempt to fight for the rights of the women. Hengameh Shahidi, Alieh Eghdam Doust, Bahareh Hedayat and Mahdiyeh Golrou have all been sent to Tehran's notorious Evin Prison on trumped-up charges related to their activism. And while Nobel Peace Prize laureate Shirin Ebadi, arguably the most internationally recognized Iranian women's rights activist, remains unable to safely return to her country, the government is targeting those affiliated with her for arrest and imprisonment, including her lawyer Nasrin Sotoudeh and her former aide Jinous Sobhani. Since the 2009 disputed elections and associated government crackdown on the overall reform movement, the government has increasingly targeted women activists. The reasons behind this go well beyond the misogynist nature of Iran's religious leadership. Rather, it is more part of a deliberate and calculated strategy of the Iranian authorities to strike at the heart of the regime's greatest vulnerability -- internal legitimacy with its own people. See more CNN.com opinion articles Iran's government recognizes and fears the broader power of the women activists who have been on the front line of reform in Iran for more than a decade. One can roughly draw an analogy between the women's movement in Iran to movements of religious groups in Burma or Tibet, or the labor "solidarity" movements in the former Eastern bloc and associated labor-Roman Catholic solidarity in Poland -- all advocating initially for the freedoms of a specific group but which provoked government fears for their transformative power to promote broader human rights progress. While the outside world occasionally reacts to the most egregious manifestations of Iran's repression of women -- such as the international condemnation associated with Sakineh Mohammadi Ashtiani, an Iranian widow sentenced to stoning on charges of alleged adultery -- these events are often portrayed simply as a consequence of the regime's archaic viewpoint about gender.
Do you have any questions?
MY QUESTION: Why was Shiva Nazar Ahari put in prison?

QUES: Plants also detect the daily cycle of light and darkness. Do you know how plants respond to these changes? Some plants open their leaves during the day. It is during these hours the plant can collect sunlight. At night, the plant closes its leaves to prevent water loss. Many plants respond to the change in the length of the day. As days grow shorter, some plants respond by going dormant. Dormant is when a plant suspends its growth. It does this in order to survive. Shorter days signal the coming of winter. Winter in most areas means extreme cold. It is also very dry in the winter months. As winter approaches, some plants respond by their leaves changing color. After the change in color, they fall off. This dormancy period helps trees. It allows them to survive the cold and dry winter. Plants only want to grow when conditions are right.
Do you have any questions?
MY QUESTION: How do plants respond to changes in light conditions during the day and night?

QUES: When American 11 struck the World Trade Center at 8:46, no one in the White House or traveling with the President knew that it had been hijacked. While that information circulated within the FAA, we found no evidence that the hijacking was reported to any other agency in Washington before 8:46. Most federal agencies learned about the crash in New York from CNN. Within the FAA, the administrator, Jane Garvey, and her acting deputy, Monte Belger, had not been told of a confirmed hijacking before they learned from television that a plane had crashed. Others in the agency were aware of it, as we explained earlier in this chapter. Inside the National Military Command Center, the deputy director of operations and his assistant began notifying senior Pentagon officials of the incident. At about 9:00, the senior NMCC operations officer reached out to the FAA operations center for information. Although the NMCC was advised of the hijacking of American 11, the scrambling of jets was not discussed. In Sarasota, Florida, the presidential motorcade was arriving at the Emma E. Booker Elementary School, where President Bush was to read to a class and talk about education. White House Chief of Staff Andrew Card told us he was standing with the President outside the classroom when Senior Advisor to the President Karl Rove first informed them that a small, twin-engine plane had crashed into the World Trade Center. The President's reaction was that the incident must have been caused by pilot error. At 8:55, before entering the classroom, the President spoke to National Security Advisor Condoleezza Rice, who was at the White House. She recalled first telling the President it was a twin-engine aircraft-and then a commercial aircraft-that had struck the World Trade Center, adding "that's all we know right now, Mr. President." At the White House, Vice President Dick Cheney had just sat down for a meeting when his assistant told him to turn on his television because a plane had struck the NorthTower of the World Trade Center. The Vice President was wondering "How the hell could a plane hit the World Trade Center" when he saw the second aircraft strike the South Tower. Elsewhere in the White House, a series of 9:00 meetings was about to begin. In the absence of information that the crash was anything other than an accident, the White House staff monitored the news as they went ahead with their regular schedules.
Do you have any questions?
MY QUESTION:
Who was standing next to the president when his reaction was that the crash of American 11 must be pilot error?