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Aceleração devido à Gravidade na Terra
A segunda lei de Newton está intimamente relacionada com a sua primeira lei do movimento. Matematicamente, ela estabelece a relação de causa e efeito…
Considere uma senhora empurrando um carrinho de bagagem enquanto se move. A força externa exercida por ela acelera o carrinho na direção da força aplicada.
Se ela empurrar com uma força maior, o carrinho se moverá mais rápido. Para parar o carrinho, ela precisa aplicar uma força externa na direção oposta ao seu movimento.
Se ela colocar mais bagagem no carrinho, a mesma força produz uma aceleração menor na direção da força externa líquida.
Compilando-os, obtemos a segunda lei do movimento de Newton, que afirma que um objeto acelera proporcionalmente e na direção da força externa líquida e inversamente à sua massa.
Ou, a força externa resultante que atua sobre um objeto é o produto de sua massa e sua aceleração. Todos os objetos em aceleração seguem a segunda lei de Newton.
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Q1: What is acceleration due to gravity on Earth?
Acceleration due to gravity is the rate at which objects accelerate toward Earth's surface when falling freely under gravitational force alone. On Earth, this value is approximately 9.8 meters per second squared (m/s²). This constant applies to all objects regardless of mass, making it a fundamental constant in physics and mechanics.
Q2: Why does gravitational acceleration remain constant near Earth's surface?
Gravitational acceleration is constant near Earth's surface because the gravitational force acting on an object is proportional to its mass, and this force divided by mass yields a constant value. The distance from Earth's center remains relatively unchanged at the surface, so the acceleration remains approximately 9.8 m/s² for all objects in free fall.
Q3: How does mass affect an object's acceleration due to gravity?
Mass does not affect an object's acceleration due to gravity. Although gravitational force increases with mass, the acceleration remains constant at 9.8 m/s² because force and mass are proportionally related. This means a feather and a bowling ball accelerate at the same rate when falling freely in a vacuum.
Q4: What is the relationship between weight and gravitational acceleration?
Weight is the gravitational force exerted on an object and is calculated by multiplying mass by gravitational acceleration (W = mg). Since gravitational acceleration on Earth is 9.8 m/s², an object's weight increases proportionally with its mass. Weight varies with location, while mass remains constant.
Q5: How does altitude affect gravitational acceleration on Earth?
Gravitational acceleration decreases slightly with increasing altitude because distance from Earth's center increases. At higher elevations, objects experience slightly less gravitational acceleration than the standard 9.8 m/s² at sea level. This effect becomes more pronounced at extreme altitudes, such as in space or on mountains.
Q6: Why is gravitational acceleration important in mechanical engineering calculations?
Gravitational acceleration is essential for calculating forces, motion, and energy in mechanical systems. Engineers use the 9.8 m/s² value to determine structural loads, design safety systems, and predict object motion. Accurate gravitational acceleration values ensure reliable predictions of system behavior and component performance.