Physics of Falling Objects and Terminal Velocity

Falling Objects and Terminal Velocity

• When an object begins to fall, gravity acts upon it, pulling it downwards. This force is known as weight.
• As the object accelerates downwards, it encounters air resistance, which acts in the opposite direction of the weight.
• Air resistance, also known as drag, is caused by the collisions between the falling object and air particles.
• The magnitude of air resistance depends on the object's surface area and velocity.
• A larger surface area allows for more collisions with air particles, increasing air resistance.
• A higher velocity leads to more frequent collisions with air particles, also increasing air resistance.
• The resultant force on a falling object is the sum of the weight and air resistance.
• Initially, the weight is larger than the air resistance, causing a downward resultant force and acceleration.
• As velocity increases, air resistance also increases until it eventually balances out the weight.
• When weight and air resistance are equal, the resultant force becomes zero, resulting in no further acceleration.
• This constant velocity is called terminal velocity.
• Changing an object's surface area, such as opening a parachute, alters air resistance and subsequently the terminal velocity.
• Increased surface area (like a parachute) increases air resistance, leading to a lower terminal velocity.

Falling Objects and Gravity

• Gravity pulls objects downwards, creating a force called weight.
• As an object falls, it encounters air resistance.

Air Resistance

• Air resistance, also known as drag, arises from collisions between a falling object and air particles.
• The magnitude of air resistance increases with:
  • A larger surface area, allowing more collisions.
  • Higher velocity, leading to more frequent collisions.

Resultant Force and Acceleration

• The resultant force on a falling object is the sum of weight and air resistance.
• Initially, weight is larger than air resistance, causing downward acceleration.
• As velocity increases, air resistance increases until it balances out the weight.

Terminal Velocity

• When weight and air resistance are equal, the resultant force becomes zero, resulting in no further acceleration.
• This constant velocity is known as terminal velocity.

Changing Terminal Velocity

• Altering an object's surface area, like opening a parachute, changes air resistance and terminal velocity.
• Increased surface area (like a parachute) increases air resistance, resulting in a lower terminal velocity.

Mass

• Mass is a measure of the amount of matter in an object.
• Mass is a scalar quantity, meaning it only has magnitude.
• The SI unit for mass is the kilogram (kg).
• Mass is a property of an object that resists change in motion.
• The greater the mass of an object, the more difficult it is to speed it up, slow it down, or change its direction.

Weight

• Weight is a gravitational force acting on an object with mass.
• Weight is a vector quantity because it has both magnitude and direction.
• The SI units for weight are Newtons (N).
• Weight is the effect of a gravitational field on a mass.
• The weight of a body is equal to the product of its mass (m) and the acceleration of free fall (g).

Gravitational Field Strength

• Gravitational field strength is defined as the force per unit mass acting on an object in a gravitational field.
• On Earth, the gravitational field strength is equal to 9.81 N/kg.
• Gravitational field strength is also known as acceleration of free fall, or acceleration due to gravity.
• The units used for gravitational field strength are m/s².

Mass vs. Weight

• An object's mass remains constant regardless of location.
• An object's weight will differ depending on the strength of the gravitational field it experiences.
• For example, the gravitational field strength on the Moon is 1.63 N/kg, so an object's weight will be about 6 times less than on Earth.

Using a Balance

• The weight of two objects can be compared using a balance.
• Because the gravitational field strength (g) is constant everywhere on Earth, a balance can be used to measure the mass of an object.

Explore the concepts of gravity, weight, and air resistance in falling objects. This quiz examines how these forces impact the motion of objects as they accelerate and eventually reach terminal velocity. Test your understanding of these fundamental principles of physics.