White clothes are cooler than black clothes because they [B] reflect whatever light reaches them. Unlike black clothes, which absorb most of the light that strikes them, white clothes reflect a significant portion of sunlight, including infrared radiation. This reflection reduces the amount of heatRead more
White clothes are cooler than black clothes because they [B] reflect whatever light reaches them. Unlike black clothes, which absorb most of the light that strikes them, white clothes reflect a significant portion of sunlight, including infrared radiation. This reflection reduces the amount of heat absorbed by the fabric, keeping the clothing and the wearer cooler. Black clothes, on the other hand, absorb light across the visible spectrum and convert it into heat energy, leading to higher temperatures. By reflecting sunlight instead of absorbing it, white clothes maintain lower temperatures and offer better comfort in hot conditions. Therefore, the reflective nature of white clothes (option [B]) is the reason behind their cooler feel compared to black clothes. Options [A], [C], and [D] do not accurately describe the phenomenon of why white clothes are cooler.
The morning sun is not as hot as the afternoon sun primarily because, in the morning, the sun's rays have to travel a greater distance through the Earth's atmosphere before reaching the surface. This longer path results in increased scattering and absorption of solar radiation by air molecules and pRead more
The morning sun is not as hot as the afternoon sun primarily because, in the morning, the sun’s rays have to travel a greater distance through the Earth’s atmosphere before reaching the surface. This longer path results in increased scattering and absorption of solar radiation by air molecules and particles, reducing the intensity of sunlight. Consequently, less solar energy reaches the Earth’s surface during the morning hours, leading to cooler temperatures compared to the afternoon. The Earth’s position relative to the sun remains relatively constant throughout the day, so it being further away in the morning (option [C]) is not a significant factor in temperature variation. Neither do the sun’s rays move slower (option [A]) nor is the sun inherently cooler in the morning (option [B]). Therefore, option [D] accurately explains why the morning sun is not as hot as the afternoon sun.
Dark-skinned people from Africa, due to higher levels of melanin in their skin, generally [A] feel more heat compared to white-skinned people from Britain. Melanin, responsible for skin pigmentation, absorbs sunlight and dissipates heat more slowly, resulting in a higher retention of heat within theRead more
Dark-skinned people from Africa, due to higher levels of melanin in their skin, generally [A] feel more heat compared to white-skinned people from Britain. Melanin, responsible for skin pigmentation, absorbs sunlight and dissipates heat more slowly, resulting in a higher retention of heat within the body. In hot environments, this can lead to increased discomfort and a heightened perception of heat. In contrast, white-skinned individuals possess less melanin, allowing for more efficient dissipation of heat, thus experiencing less discomfort from heat exposure. While both groups may experience variations in their perception of heat based on factors such as humidity and individual tolerance levels, the physiological difference in melanin levels predisposes darker-skinned individuals to feel more heat compared to their lighter-skinned counterparts. Therefore, option [A] is the most appropriate choice.
The most appropriate color combination for sun protection among the options provided is [B] White above and black below. White reflects sunlight, helping to keep the area beneath the umbrella cooler by deflecting heat. Black absorbs sunlight, effectively preventing it from passing through the umbrelRead more
The most appropriate color combination for sun protection among the options provided is [B] White above and black below. White reflects sunlight, helping to keep the area beneath the umbrella cooler by deflecting heat. Black absorbs sunlight, effectively preventing it from passing through the umbrella, thus providing shade. This combination creates a balance between reflection and absorption, maximizing sun protection. Black underneath also reduces glare from below, enhancing visibility and comfort. Conversely, [A] Black above and white below might absorb more heat from the sun, potentially making the shaded area warmer. [C] Both black above and below could result in excessive heat absorption, making the shaded area uncomfortably warm. [D] Both white above and below lack the contrast needed for effective sun protection, potentially allowing more sunlight to pass through. Therefore, option [B] is the most suitable for sun protection.
The primary reason clothes keep us warm in winter is [D] Prevent body heat from going out. Our bodies naturally generate heat through metabolic processes, and this heat can be lost to the surrounding environment, especially when it is cold outside. Clothes act as insulators, creating a barrier thatRead more
The primary reason clothes keep us warm in winter is [D] Prevent body heat from going out. Our bodies naturally generate heat through metabolic processes, and this heat can be lost to the surrounding environment, especially when it is cold outside. Clothes act as insulators, creating a barrier that reduces the rate at which body heat escapes.
When we wear clothes, especially those made of materials with good insulating properties such as wool, fleece, or down, they trap air close to the skin. Air is a poor conductor of heat, so this trapped layer of air acts as an additional insulating layer, further reducing heat loss. This insulation is crucial in maintaining a stable and comfortable body temperature in cold weather.
Options [A], [B], and [C] do not accurately describe how clothing keeps us warm. Clothes do not provide heat (Option [A]); instead, they help retain the heat our bodies generate. Option [B] is incorrect because all materials, including clothes, can radiate heat to some extent. However, good insulating clothes minimize this radiation. Option [C] is partially correct in that preventing cold air from directly contacting the skin helps maintain warmth, but the main function of clothes is to retain the body’s heat.
In summary, the effectiveness of clothes in keeping us warm lies primarily in their ability to prevent body heat from escaping, thereby maintaining our internal body temperature in cold conditions.
Why are white clothes cooler than black clothes?
White clothes are cooler than black clothes because they [B] reflect whatever light reaches them. Unlike black clothes, which absorb most of the light that strikes them, white clothes reflect a significant portion of sunlight, including infrared radiation. This reflection reduces the amount of heatRead more
White clothes are cooler than black clothes because they [B] reflect whatever light reaches them. Unlike black clothes, which absorb most of the light that strikes them, white clothes reflect a significant portion of sunlight, including infrared radiation. This reflection reduces the amount of heat absorbed by the fabric, keeping the clothing and the wearer cooler. Black clothes, on the other hand, absorb light across the visible spectrum and convert it into heat energy, leading to higher temperatures. By reflecting sunlight instead of absorbing it, white clothes maintain lower temperatures and offer better comfort in hot conditions. Therefore, the reflective nature of white clothes (option [B]) is the reason behind their cooler feel compared to black clothes. Options [A], [C], and [D] do not accurately describe the phenomenon of why white clothes are cooler.
See lessThe morning sun is not as hot as the afternoon sun, because
The morning sun is not as hot as the afternoon sun primarily because, in the morning, the sun's rays have to travel a greater distance through the Earth's atmosphere before reaching the surface. This longer path results in increased scattering and absorption of solar radiation by air molecules and pRead more
The morning sun is not as hot as the afternoon sun primarily because, in the morning, the sun’s rays have to travel a greater distance through the Earth’s atmosphere before reaching the surface. This longer path results in increased scattering and absorption of solar radiation by air molecules and particles, reducing the intensity of sunlight. Consequently, less solar energy reaches the Earth’s surface during the morning hours, leading to cooler temperatures compared to the afternoon. The Earth’s position relative to the sun remains relatively constant throughout the day, so it being further away in the morning (option [C]) is not a significant factor in temperature variation. Neither do the sun’s rays move slower (option [A]) nor is the sun inherently cooler in the morning (option [B]). Therefore, option [D] accurately explains why the morning sun is not as hot as the afternoon sun.
See lessDark-skinned people from Africa compared to white-skinned people from Britain
Dark-skinned people from Africa, due to higher levels of melanin in their skin, generally [A] feel more heat compared to white-skinned people from Britain. Melanin, responsible for skin pigmentation, absorbs sunlight and dissipates heat more slowly, resulting in a higher retention of heat within theRead more
Dark-skinned people from Africa, due to higher levels of melanin in their skin, generally [A] feel more heat compared to white-skinned people from Britain. Melanin, responsible for skin pigmentation, absorbs sunlight and dissipates heat more slowly, resulting in a higher retention of heat within the body. In hot environments, this can lead to increased discomfort and a heightened perception of heat. In contrast, white-skinned individuals possess less melanin, allowing for more efficient dissipation of heat, thus experiencing less discomfort from heat exposure. While both groups may experience variations in their perception of heat based on factors such as humidity and individual tolerance levels, the physiological difference in melanin levels predisposes darker-skinned individuals to feel more heat compared to their lighter-skinned counterparts. Therefore, option [A] is the most appropriate choice.
See lessWhich of the following colour combinations of umbrellas is most appropriate for protection from the sun?
The most appropriate color combination for sun protection among the options provided is [B] White above and black below. White reflects sunlight, helping to keep the area beneath the umbrella cooler by deflecting heat. Black absorbs sunlight, effectively preventing it from passing through the umbrelRead more
The most appropriate color combination for sun protection among the options provided is [B] White above and black below. White reflects sunlight, helping to keep the area beneath the umbrella cooler by deflecting heat. Black absorbs sunlight, effectively preventing it from passing through the umbrella, thus providing shade. This combination creates a balance between reflection and absorption, maximizing sun protection. Black underneath also reduces glare from below, enhancing visibility and comfort. Conversely, [A] Black above and white below might absorb more heat from the sun, potentially making the shaded area warmer. [C] Both black above and below could result in excessive heat absorption, making the shaded area uncomfortably warm. [D] Both white above and below lack the contrast needed for effective sun protection, potentially allowing more sunlight to pass through. Therefore, option [B] is the most suitable for sun protection.
See lessClothes keep us warm in winter because
The primary reason clothes keep us warm in winter is [D] Prevent body heat from going out. Our bodies naturally generate heat through metabolic processes, and this heat can be lost to the surrounding environment, especially when it is cold outside. Clothes act as insulators, creating a barrier thatRead more
The primary reason clothes keep us warm in winter is [D] Prevent body heat from going out. Our bodies naturally generate heat through metabolic processes, and this heat can be lost to the surrounding environment, especially when it is cold outside. Clothes act as insulators, creating a barrier that reduces the rate at which body heat escapes.
When we wear clothes, especially those made of materials with good insulating properties such as wool, fleece, or down, they trap air close to the skin. Air is a poor conductor of heat, so this trapped layer of air acts as an additional insulating layer, further reducing heat loss. This insulation is crucial in maintaining a stable and comfortable body temperature in cold weather.
Options [A], [B], and [C] do not accurately describe how clothing keeps us warm. Clothes do not provide heat (Option [A]); instead, they help retain the heat our bodies generate. Option [B] is incorrect because all materials, including clothes, can radiate heat to some extent. However, good insulating clothes minimize this radiation. Option [C] is partially correct in that preventing cold air from directly contacting the skin helps maintain warmth, but the main function of clothes is to retain the body’s heat.
In summary, the effectiveness of clothes in keeping us warm lies primarily in their ability to prevent body heat from escaping, thereby maintaining our internal body temperature in cold conditions.
See less