Question: Why is respiration considered an exothermic reaction explain? Respiration is the process of breaking down food molecules in living cells to release energy. This energy can be used for various purposes, such as heat, movement, growth and active uptake. Respiration is considered an exothermic reaction because it releases heat into the surroundings as a byproduct. How does respiration release heat? To understand this, we need to look at the chemical equation of respiration. The most common food molecule that is respired is glucose, which has the formula C6H12O6. Glucose reacts with oxygen (O2) in the mitochondria of cells to produce carbon dioxide (CO2) and water (H2O). The equation for this reaction is: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy The energy that is released in this reaction is mainly in the form of heat. This is because the bonds that are formed in the products (CO2 and H2O) are more stable than the bonds that are broken in the reactants (C6H12O6 and O2). Stable bonds
A ball is thrown upwards and returns to the same location. when it turns, how much is the speed compared with the initial speed?
Question: A ball is thrown upwards and returns to the same location. when it turns, how much is the speed compared with the initial speed? When a ball is thrown upwards and returns to the same location, its speed when it returns will be equal to its initial speed, but in the opposite direction. Assuming there is no significant air resistance, the ball's speed gradually decreases as it moves upward due to the force of gravity acting against it. At the highest point of its trajectory, its speed becomes zero momentarily. Then, as the ball falls back down, it gains speed due to the acceleration from gravity. When the ball reaches its starting point, its speed will be the same as the initial speed, but in the opposite direction. This is because the force of gravity acts to accelerate the ball downward, reversing its initial upward velocity. Therefore, the speed of the ball when it returns to the same location is equal in magnitude but opposite in direction to its initial speed.