praxis elementary science 5005 practice test

A series of tests developed by ETS to assess the skills and knowledge of prospective teachers.

An astronaut travels to the Moon, where the magnitude of the force of gravity is one-sixth the magnitude of the force of gravity on Earth. On the Moon, which of the following is true?
  • A. The astronaut's mass is one-sixth of his mass on Earth.
  • B. The astronaut's weight is one-sixth of his weight on Earth.
  • C. The astronaut's mass is six times his mass on Earth.
  • D. The astronaut's weight is six times his weight on Earth.
Correct Answer & Rationale
Correct Answer: B

An astronaut's mass remains constant regardless of location; therefore, option A is incorrect as mass on the Moon is the same as on Earth. Option C is also incorrect because mass does not change based on gravitational force. Option D misrepresents weight; weight is dependent on gravity, and since the Moon's gravity is one-sixth that of Earth's, the astronaut's weight is one-sixth, not six times. Thus, option B accurately reflects that the astronaut's weight on the Moon is one-sixth of his weight on Earth, aligning with the relationship between weight and gravitational force.

Other Related Questions

Which of the following is true about the nucleus of an atom?
  • A. The nucleus has a negative charge.
  • B. The nucleus is neutral with no charge.
  • C. The electrons and protons are located in the nucleus.
  • D. The neutrons and protons are located in the nucleus.
Correct Answer & Rationale
Correct Answer: D

The nucleus of an atom is composed of protons and neutrons, making option D accurate. Protons carry a positive charge, while neutrons are neutral, contributing to the overall positive charge of the nucleus. Option A is incorrect because the nucleus does not have a negative charge; it is positively charged due to protons. Option B is also wrong, as the nucleus is not neutral; it has a positive charge from the protons. Lastly, option C is misleading because electrons are located outside the nucleus in electron shells, not within it.
Which THREE of the following are health problems associated with long-term exposure to air pollution?
  • A. Accelerated aging of the lungs
  • B. Increased lung capacity
  • C. Increased risk of asthma
  • D. Increased risk of cardiovascular disease
Correct Answer & Rationale
Correct Answer: A,C,D

Long-term exposure to air pollution can lead to several significant health issues. Option A, accelerated aging of the lungs, is accurate as pollutants can damage lung tissue over time, reducing function. Option C is also correct; exposure to air pollution is linked to a higher incidence of asthma, particularly in children, due to airway inflammation and increased sensitivity. Option D is valid as well; numerous studies show that air pollution significantly raises the risk of cardiovascular diseases due to systemic inflammation and oxidative stress. Conversely, Option B, increased lung capacity, is incorrect. Air pollution typically impairs lung function rather than enhancing it, leading to reduced capacity over time.
Which THREE of the following processes depend directly on energy from the Sun?
  • A. Seafloor spreading
  • B. The water cycle
  • C. Photosynthesis
  • D. Atmospheric circulation
Correct Answer & Rationale
Correct Answer: B,C,D

Energy from the Sun drives several essential processes on Earth. **The water cycle (B)** relies on solar energy to evaporate water from oceans and lakes, facilitating condensation and precipitation. **Photosynthesis (C)** is directly powered by sunlight, as plants convert solar energy into chemical energy, producing oxygen and glucose. **Atmospheric circulation (D)** is influenced by solar heating, which creates temperature gradients that drive wind patterns and weather systems. In contrast, **seafloor spreading (A)** is a geological process driven by tectonic activity and heat from the Earth's interior, not solar energy.
Which TWO of the following statements about the universe are true?
  • A. The universe is expanding.
  • B. The Milky Way galaxy contains most of the stars in the universe.
  • C. A star's size, temperature, and composition typically remain constant throughout its life cycle.
  • D. A black hole is usually detected by the intense visible light it emits.
Correct Answer & Rationale
Correct Answer: A

Option A accurately reflects current astronomical understanding, as evidence shows the universe is expanding due to the redshift of distant galaxies. Option B is incorrect; while the Milky Way is large, it contains only a small fraction of the universe's stars, which are spread across billions of galaxies. Option C is misleading; stars undergo significant changes in size, temperature, and composition throughout their life cycles, particularly during phases like red giant or supernova. Option D is also false; black holes do not emit visible light; they are detected through their gravitational effects and the radiation from material falling into them.