Long answer questions
E. Answer in detail.
1. Discuss the effects of heat.
2. How is a smaller metal rim fixed on a bigger
wooden wheel?
C
3. Describe a simple experiment to show that
solids expand on heating.
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Answers
Question :-
Answer in detail.
1. Discuss the effects of heat.
2. How is a smaller metal rim fixed on a bigger
wooden wheel?
3. Describe a simple experiment to show that
solids expand on heating.
Answer :-
1 . Effects of Heat :
Climate and Human Health
- Prolonged exposure to extreme heat can cause heat exhaustion, heat cramps, heat stroke, and death, as well as exacerbate preexisting chronic conditions, such as various respiratory, cerebral, and cardiovascular diseases. These serious health consequences usually affect more vulnerable populations such as the elderly, children, and those with existing cardiovascular and respiratory diseases.
- Socioeconomic factors, such as economically disadvantaged and socially isolated individuals, are also at risk from heat-related burdens. As global temperatures rise and extreme heat events increase in frequency due to climate change we can expect to see more heat-related illnesses and mortality.
- Public health systems need to be prepared for extreme events and responses will demand a concerted effort among the public health community, the medical establishment, emergency responses teams, the housing authority, and law enforcement in order to quickly identify and serve the populations vulnerable to extreme heat events.
Health Impacts
- Increased temperatures and increase in extreme heat events cause heat exhausting, heat stroke, and death, especially in vulnerable populations.
- High concentrations of buildings in urban areas cause urban heat island effect, generation and absorbing heat, making the urban center several degrees warmer than surrounding areas.
Mitigation and Adaptation
- Heat early warning systems and proactive heat wave response plans
- Increased air conditioning use
- Decreased time spent outdoors during extreme heat events
- Increased use of sun-shielding clothing
Research Needs
- Developing and implementing a standard definition of heat-related health outcomes, as well as standard methodologies for surveillance of outcomes and evaluation of adaptations
- Understanding risk factors for illness and death associated with both acute exposure to extreme heat events and long-term, chronic exposure to increased average temperatures
- Quantifying the combined effects of exposure to heat waves and ambient air pollution on excessive illness and death
- Determining attributes of communities, including regional and seasonal differences, that are more resilient or vulnerable to adverse health impacts from heat waves
- Assessing the health benefits of the use of environmental design principles to reduce high thermal mass of urban areas
- Enhancing the ability of current climate models to capture the observed frequency and intensity of heat waves across various timescales to support weather-climate predictions and use of heat early warning systems in decision making
- Evaluating heat response plans, focusing on environmental risk factors, identification of high-risk populations, effective communications strategies, and rigorous methods for evaluating effectiveness on the local level
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2 . The metal rim is always made slightly smaller than the wooden wheel. The metal rim is heated on heating the rim expands and fit onto the wheel. Cold water is then poured over the rim due to cooling the metal rim contracts and fits tightly onto the wooden wheel
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3 . Take a metallic ball and ring. The diameters of the ring and the ball are such that ball is just able to pass through the ring at the room temperature. Now heat the ball and try to pass the ball through the ring. It does not pass through the ring as shown in the figure ( Refer the attachment ♡ )
This clearly shows that on heating the diameter of the ball has increased i.e., the solid has expanded. Now cool the ball to room temperature. After cooling it is found that ball passes through the ring which clearly shows that diameter of the ball has decreased, i.e., the solid contracts on cooling.
