An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
In 30 seconds, approximately 2.81 × 1 0 21 electrons flow through an electric device with a current of 15.0 A . This is calculated using the relation between current, charge, and the charge of a single electron. Therefore, for a specified current and time, you can find the total charge and then calculate the number of electrons based on their individual charge.
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Nutrition is the process through which living organisms obtain and utilize the foods needed for growth, maintenance, and energy. It involves the intake of food, digestion, absorption, assimilation, and waste elimination. Nutrition is crucial because it ensures that the body receives all the essential nutrients—such as vitamins, minerals, carbohydrates, proteins, and fats—that are necessary for health, growth, and survival.
There are two main types of nutrition based on how organisms obtain their food:
Autotrophs : These are organisms that can produce their own food. They use simple inorganic substances like carbon dioxide and water to synthesize organic compounds through processes such as photosynthesis or chemosynthesis. Plants, algae, and certain bacteria are examples of autotrophs. They are also known as producers in the food chain.
Heterotrophs : These are organisms that cannot produce their own food and must consume other organisms to obtain their nutrients. Humans, animals, fungi, and many bacteria fall under this category. Heterotrophs rely on autotrophs and other heterotrophs for their energy and nutrient needs. They are considered consumers in the food chain.
The statement 'Humans and other animals are directly or indirectly dependent on plants' is justified by the fact that plants are primary producers that can convert sunlight into energy through photosynthesis. This energy is stored in the form of glucose and other carbohydrates, which are essential for the survival of both autotrophs and heterotrophs.
Direct Dependence : Herbivores, animals that eat plants, directly depend on plants for nutrition. Examples include cows, deer, and rabbits.
Indirect Dependence : Carnivores, animals that eat other animals, indirectly rely on plants. These animals prey on herbivores or other carnivores that are part of a plant-based food chain. Humans, being omnivores, fall into both categories since they can directly consume plants or indirectly consume them by eating plant-eating animals.
Therefore, plants form the base of the ecological pyramid, supporting all other life forms by providing the essential energy and nutrients needed for survival and growth.
