praxis elementary science 5005 practice test

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

Which TWO of the following are true statements about hurricanes?
  • A. They are typically over 160 kilometers, or 100 miles, in diameter.
  • B. They form over cold water in Earth's polar regions and move slowly.
  • C. They develop quickly and usually last for less than 30 minutes.
  • D. They can have sustained wind speeds that are over 200 kilometers per hour.
Correct Answer & Rationale
Correct Answer: A, D

Hurricanes are vast systems, often exceeding 160 kilometers (100 miles) in diameter, making option A true. Additionally, they can reach sustained wind speeds over 200 kilometers per hour, confirming option D. In contrast, option B is incorrect as hurricanes form over warm waters, typically in tropical regions, not cold polar waters. Moreover, they do not move slowly; they can travel at significant speeds. Option C is also false; while hurricanes can develop rapidly, they generally last for several days, not just 30 minutes. Understanding these characteristics is crucial for recognizing the nature and impact of hurricanes.

Other Related Questions

Which of the following best explains why an ice skater is able to coast on ice for a long distance without pushing off in a straight line across the ice?
  • A. The force of friction on the blades of the skates is greater than the force of friction on the ice.
  • B. The force of friction on the blades of the skates is less than the force of friction on the ice.
  • C. The ice exerts a constant forward force on the skater.
  • D. The buoyant force on the blades of the skates is greater than the weight of the skater.
Correct Answer & Rationale
Correct Answer: B

An ice skater can glide smoothly due to the minimal friction between the skate blades and the ice, which is significantly lower than the friction experienced on other surfaces. This reduced friction allows the skater to maintain momentum over longer distances without needing to push off. Option A is incorrect because it suggests greater friction on the blades, which would hinder movement. Option C is misleading, as the ice does not exert a forward force; instead, the skater continues moving due to existing momentum. Option D is also wrong; while buoyancy affects weight in water, it does not apply to ice skating, where weight and friction are the primary factors.
The speed of light in empty space, that is, a vacuum, is 300,000 km/s. The speed of sound in empty space is:
  • B. greater than 0 but less than 300,000 km/s
  • C. 300,000 km/s
  • D. greater than 300,000 km/s
Correct Answer & Rationale
Correct Answer: A

The speed of sound requires a medium, such as air or water, to propagate; it cannot travel through a vacuum. Therefore, the speed of sound in empty space is effectively zero. Option B suggests that the speed of sound is greater than 0 but less than 300,000 km/s, which is incorrect because sound cannot exist in a vacuum. Option C states it is 300,000 km/s, which misrepresents sound's nature, as this speed is specific to light. Option D claims it is greater than 300,000 km/s, which is impossible since sound cannot travel in a vacuum at all. Thus, the only valid conclusion is that the speed of sound in empty space is zero.
A neutral atom always contains an equal number of which of the following?
  • A. Protons and electrons
  • B. Protons and neutrons
  • C. Neutrons and electrons
  • D. Protons and alpha particles
Correct Answer & Rationale
Correct Answer: A

A neutral atom contains an equal number of protons and electrons, ensuring that the positive and negative charges balance each other out, resulting in no overall charge. Option B is incorrect because protons and neutrons do not need to be equal; the number of neutrons can vary, leading to different isotopes. Option C is also wrong, as neutrons do not have a charge and do not balance with electrons, which are negatively charged. Lastly, option D is incorrect since alpha particles, which consist of two protons and two neutrons, are not found in neutral atoms and do not play a role in charge balance.
Which of the following best predicts what will happen when white light passes through a green object?
  • A. The object will mostly reflect the green part of the light.
  • B. The object will mostly absorb the green part of the light.
  • C. The object will appear black.
  • D. The object will appear white.
Correct Answer & Rationale
Correct Answer: A

When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.