Acceleration Due to Gravity

Definition

Acceleration due to gravity, often denoted as 'g', is the rate at which an object's velocity changes due to the Earth's gravitational pull. This constant acceleration is experienced by all objects near the Earth's surface, regardless of their mass or composition, and plays a crucial role in the study of motion and the application of Newton's laws of motion.

5 Must Know Facts For Your Next Test

1. The value of acceleration due to gravity, 'g', is approximately 9.8 m/s^2 near the Earth's surface.
2. Acceleration due to gravity is a constant, meaning it does not change with the mass of the object or the height above the Earth's surface (within a reasonable range).
3. Acceleration due to gravity is directed downwards, towards the center of the Earth, and is the primary cause of objects falling at a constant rate.
4. The acceleration due to gravity can be used to calculate the weight of an object, which is the force exerted on the object by the Earth's gravitational pull.
5. Acceleration due to gravity is a key factor in the study of projectile motion, where an object is launched into the air and experiences both horizontal and vertical acceleration.

Review Questions

• How does the acceleration due to gravity affect the motion of an object in free fall?
  • The acceleration due to gravity, 'g', is the constant acceleration experienced by an object in free fall, meaning it is falling solely under the influence of the Earth's gravitational pull and not acted upon by any other external forces. This constant acceleration causes the object's velocity to increase at a steady rate, with the object's position changing in a parabolic trajectory. The value of 'g' is approximately 9.8 m/s^2, which means an object in free fall will accelerate downward at that rate, regardless of its mass or composition.
• Explain how the acceleration due to gravity is related to the concept of weight and its calculation.
  • The acceleration due to gravity, 'g', is a key factor in determining the weight of an object. Weight is defined as the force exerted on an object by the Earth's gravitational pull, and it is calculated by multiplying the object's mass by the acceleration due to gravity. This relationship is expressed in the formula: $W = m \times g$, where 'W' is the weight, 'm' is the mass, and 'g' is the acceleration due to gravity. Therefore, the value of 'g' directly influences the weight of an object, with a higher 'g' value resulting in a greater weight for the same mass.
• Discuss the importance of understanding acceleration due to gravity in the context of vector addition and subtraction, as covered in the 5.2 Vector Addition and Subtraction: Analytical Methods topic.
  • Acceleration due to gravity is a crucial concept in the study of vector addition and subtraction, as it represents a constant vector quantity that must be considered when analyzing the motion of objects. In the context of 5.2 Vector Addition and Subtraction: Analytical Methods, the acceleration due to gravity, 'g', can be used to decompose the motion of an object into its horizontal and vertical components, allowing for the application of vector analysis techniques to solve problems involving projectile motion, inclined planes, and other scenarios where gravity plays a significant role. Understanding the magnitude and direction of the acceleration due to gravity is essential for accurately representing the forces acting on an object and applying the principles of vector addition and subtraction to determine the object's overall motion.

Related terms

Gravitational Force: The attractive force between two objects with mass, which causes objects to accelerate towards each other. The strength of this force is determined by the masses of the objects and the distance between them.

Free Fall: The motion of an object that is falling under the sole influence of gravity, without any other external forces acting upon it. In a free fall, the object experiences a constant acceleration due to gravity.

Weight: The force exerted on an object by gravity, which is equal to the object's mass multiplied by the acceleration due to gravity. Weight is a vector quantity, as it has both magnitude and direction.