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.
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.
Other Related Questions
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.
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.
A metal spoon that heats up while sitting in a bowl of hot soup is an example of heat transfer by:
- A. conduction
- B. convection
- C. radiation
- D. diffusion
Correct Answer & Rationale
Correct Answer: A
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Which of the following is a nonrenewable fossil fuel?
- A. Coal
- B. Uranium
- C. Geothermal energy
- D. Ethanol
Correct Answer & Rationale
Correct Answer: A
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.
Fossilized remains of prehistoric organisms are typically found in which of the following types of rock?
- A. Metamorphic rock
- B. Igneous rock
- C. Sedimentary rock
- D. Molten rock
Correct Answer & Rationale
Correct Answer: C
Fossilized remains are most commonly found in sedimentary rock, which forms from the accumulation of sediment and organic material in layers. This environment allows for the preservation of organisms. Metamorphic rock (A) forms under high pressure and temperature, altering existing rocks and typically destroying fossils. Igneous rock (B) is created from cooled magma or lava, which does not preserve organic material. Molten rock (D) refers to rock in a liquid state, which cannot contain fossils as it is not solidified. Thus, sedimentary rock is the ideal environment for fossil preservation.
Fossilized remains are most commonly found in sedimentary rock, which forms from the accumulation of sediment and organic material in layers. This environment allows for the preservation of organisms. Metamorphic rock (A) forms under high pressure and temperature, altering existing rocks and typically destroying fossils. Igneous rock (B) is created from cooled magma or lava, which does not preserve organic material. Molten rock (D) refers to rock in a liquid state, which cannot contain fossils as it is not solidified. Thus, sedimentary rock is the ideal environment for fossil preservation.