Concept Items
1.1 Physics: Definitions and Applications
Which of the following is not an underlying assumption essential to scientific understanding?
- Characteristics of the physical universe can be perceived and objectively measured by human beings.
- Explanations of natural phenomena can be established with absolute certainty.
- Fundamental physical processes dictate how characteristics of the physical universe evolve.
- The fundamental processes of nature operate the same way everywhere and at all times.
Which of the following questions regarding a strain of genetically modified rice is not one that can be answered by science?
- How does the yield of the genetically modified rice compare with that of existing rice?
- Is the genetically modified rice more resistant to infestation than existing rice?
- How does the nutritional value of the genetically modified rice compare to that of existing rice?
- Should the genetically modified rice be grown commercially and sold in the marketplace?
What conditions imply that we can use classical physics without considering special relativity or quantum mechanics?
-
- matter is moving at speeds of less than roughly 1 percent the speed of light,
- objects are large enough to be seen with the naked eye, and
- there is the involvement of a strong gravitational field.
-
- matter is moving at speeds greater than roughly 1 percent the speed of light,
- objects are large enough to be seen with the naked eye, and
- there is the involvement of a strong gravitational field.
-
- matter is moving at speeds of less than roughly 1 percent the speed of light,
- objects are too small to be seen with the naked eye, and
- there is the involvement of only a weak gravitational field.
-
- matter is moving at speeds of less than roughly 1 percent the speed of light,
- objects are large enough to be seen with the naked eye, and
- there is the involvement of a weak gravitational field.
Why is Einstein’s theory of relativity considered part of modern physics, as opposed to classical physics?
- Because it was considered less outstanding than the classics of physics, such as classical mechanics.
- Because it was popular physics enjoyed by average people today, instead of physics studied by the elite.
- Because the theory deals with very slow-moving objects and weak gravitational fields.
- Because it was among the new 19th-century discoveries that changed physics.
1.3 The Language of Physics: Physical Quantities and Units
How does the independent variable in a graph differ from the dependent variable?
- The dependent variable varies linearly with the independent variable.
- The dependent variable depends on the scale of the axis chosen while independent variable does not.
- The independent variable is directly manipulated or controlled by the person doing the experiment, while dependent variable is the one that changes as a result.
- The dependent and independent variables are fixed by a convention and hence they are the same.
Velocity, or speed, is measured using the following formula: where v is velocity, d is the distance travelled, and t is the time the object took to travel the distance. If the velocity-time data are plotted on a graph, which variable will be on which axis? Why?
- Time would be on the x-axis and velocity on the y-axis, because time is an independent variable and velocity is a dependent variable.
- Velocity would be on the x-axis and time on the y-axis, because time is the independent variable and velocity is the dependent variable.
- Time would be on the x-axis and velocity on the y-axis, because time is a dependent variable and velocity is a independent variable.
- Velocity would be on x-axis and time on the y-axis, because time is a dependent variable and velocity is a independent variable.