Ch. 4 – 7, 12 – 13, 15 HW
· In what sense does the moon fall?
· How does the force of gravity between two bodies change when the distance between them is tripled?
· Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that accelerated upward? Accelerated downward? Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that moved upward at a constant velocity? In an elevator that moved downward at constant velocity?
· Explain why occupants of the International Space Station are firmly in the grip of Earth’s gravity, even though they have no weight.
· A stone is thrown up at an angle. Neglecting air resistance, what happens to the horizontal component of its velocity along its trajectory? The vertical component?
· A projectile is launched vertically at 100 m/s. If air resistance can be neglected, at what speed does it return to its initial level?
· What happens to an object close to Earth’s surface if it is given a speed exceeding 11.2km/s?
· Distinguish between force and pressure.
· How does the pressure exerted by a liquid change with depth of the liquid?
· Why does buoyant force act upward on an object submerged in water?
· How does the buoyant force on a fully submerged object compare with the weigh of the water displaced?
· What are the temperatures for freezing water and boiling water on the Kelvin temperature scale?
· In which direction does thermal energy flow between hot and cold objects?
· How does heat differ from thermal energy?
· How is the energy value of food determined?
· What is the role of “loose” electrons in heat conductors?
· Describe how heat is transferred by convection
· What kind of objects give off radiant energy?
· What are the four common phases of matter, and what are the processes which transform one to another?
· Does a gas give off energy or absorb energy when it changes to a liquid? How about a solid changing into a liquid?
· Distinguish between an atom and an element.
· Distinguish between atomic number, mass number, and atomic mass.
· What happens to the properties of elements across any period of the periodic table?
· What causes an atom to emit light?
· What was Planck’s quantum hypothesis?
· What does “radioactive” mean?
· Describe the three types of radioactive radiation: alpha, beta, and gamma.
· Why doesn’t the repulsive electric force of protons in the atomic nucleus cause the protons to fly apart?
· What is meant by the half-life of a radioactive sample?
· Why is there more carbon-14 in living bones than in once-living ancient bones of the same mass?
· How is a nuclear reactor similar to a conventional fossil-fuel power plant? How is it different?
· Who discovered that energy and mass are two different forms of the same thing?
· What kind of nuclear power is responsible for sunshine?
· How many electrons can occupy the first shell? How many can occupy the second shell?
· How do the electron-dot structures of elements in the same group in the periodic table compare with one another?
· How does an ion differ from an atom?
· Why does the fluorine atom tend to gain only one electron?
· Which elements tend to form ionic bonds?
· Do metals more readily gain or lose electrons?
· Which elements tend to form covalent bonds?