Answer the following question given this paragraph: Friction is a force that opposes motion. Any two objects in contact have what is called a mutual coefficient of friction. To find the force of friction between them, we multiply the normal force by this coefficient. Like the forces above, it arises due to electromagnetic interactions of atoms in two objects. There are actually two coefficients of friction: static and kinetic. Static friction will oppose initial motion of two objects relative to each other. Once the objects are moving, however, kinetic friction will oppose their continuing motion. Kinetic friction is lower than static friction, so it is easier to keep an object in motion than to set it in motion. There are some things about friction that are not very intuitive:. Q: What is a force that opposes motion? Choices: - tension - momentum - thrust - friction A:
friction
Answer the following question given this paragraph: Farmers use greenhouses to extend the growing season. A greenhouse traps heat. Days that are too cool for a growing plant can be made to be just right. Similar to a greenhouse, greenhouse gases in the atmosphere keep Earth warm. Q: What do farmers use greenhouses for? Choices: - to predict the growing season - to allow the growing season - to decrease the growing season - to extend the growing season A:
to extend the growing season
Q: Answer the following question given this paragraph: On the ventral side of the embryonic disc, opposite the amnion, cells in the lower layer of the embryonic disk (the hypoblast) extend into the blastocyst cavity and form a yolk sac. The yolk sac supplies some nutrients absorbed from the trophoblast and also provides primitive blood circulation to the developing embryo for the second and third week of development. When the placenta takes over nourishing the embryo at approximately week 4, the yolk sac has been greatly reduced in size and its main function is to serve as the source of blood cells and germ cells (cells that will give rise to gametes). During week 3, a finger-like outpocketing of the yolk sac develops into the allantois, a primitive excretory duct of the embryo that will become part of the urinary bladder. Together, the stalks of the yolk sac and allantois establish the outer structure of the umbilical cord. The last of the extra-embryonic membranes is the chorion, which is the one membrane that surrounds all others. The development of the chorion will be discussed in more detail shortly, as it relates to the growth and development of the placenta. Q: On the ventral side of the embryonic disc, opposite the amnion, cells in the lower layer of the embryonic disk (the hypoblast) extend into the blastocyst cavity and form this? Choices: - embryo sac - neural sac - algae sac - yolk sac A:
A: yolk sac
Question: Answer the following question given this paragraph: A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition that is different from other minerals. One mineral's physical properties differ from others'. These properties include crystal structure, hardness, density and color. Each is made of different elements. Each has different physical properties. For example, silver is a soft, shiny metal. Salt is a white, cube-shaped crystal. Diamond is an extremely hard, translucent crystal. Q: A mineral can be made of an element or a? Choices: - Sediment - component - cell - compound A:
Answer: compound
*Question*
Answer the following question given this paragraph: Materials that are good conductors of thermal energy are called thermal conductors. Metals are very good thermal conductors. Q: Materials that are good conductors of thermal energy are called? Choices: - atmospheric conductors - thermal inductors - atmospheric inductors - thermal conductors A:
**Answer**
thermal conductors
Q: Answer the following question given this paragraph: Q: What two microorganisms have different membrane lipids? Choices: - microsporidia and bacteria - mesozoic and bacteria - algae and bacteria - archaea and bacteria A:
A: archaea and bacteria