## What Forces Affect a Skydiver Falling Back to Earth
When a skydiver jumps out of an airplane, they are immediately subject to the forces of gravity and air resistance. Gravity pulls the skydiver down towards the earth, while air resistance acts to slow the skydiver’s fall. The magnitude of these forces depends on a number of factors, including the skydiver’s weight, the surface area of their body, and the speed at which they are falling.
### Gravity
Gravity is the force of attraction between two objects with mass. The greater the mass of an object, the greater its gravitational pull. The earth has a very large mass, so it exerts a strong gravitational pull on objects near its surface. This pull is what causes objects to fall to the ground when they are dropped.
The force of gravity on a skydiver is proportional to their mass. A heavier skydiver will experience a greater gravitational pull than a lighter skydiver. This means that heavier skydivers will fall faster than lighter skydivers, all other things being equal.
### Air Resistance
Air resistance is the force that opposes the motion of an object through the air. The magnitude of air resistance depends on the object’s speed, surface area, and shape. The faster an object is moving, the greater the air resistance it will experience. The greater the surface area of an object, the greater the air resistance it will experience. And the more streamlined an object is, the less air resistance it will experience.
The force of air resistance on a skydiver is proportional to their speed and surface area. A skydiver who is falling at a high speed will experience greater air resistance than a skydiver who is falling at a low speed. A skydiver with a large surface area will experience greater air resistance than a skydiver with a small surface area. And a skydiver who is streamlined will experience less air resistance than a skydiver who is not streamlined.
### Terminal Velocity
The terminal velocity of an object is the speed at which the force of air resistance is equal to the force of gravity. When an object reaches its terminal velocity, it will no longer accelerate and will continue to fall at a constant speed.
The terminal velocity of a skydiver depends on their weight, surface area, and shape. A heavier skydiver will have a higher terminal velocity than a lighter skydiver. A skydiver with a larger surface area will have a higher terminal velocity than a skydiver with a smaller surface area. And a skydiver who is streamlined will have a lower terminal velocity than a skydiver who is not streamlined.
The typical terminal velocity of a skydiver is about 120 miles per hour (190 kilometers per hour). However, this can vary depending on the factors mentioned above.
### Other Forces
In addition to gravity and air resistance, there are a number of other forces that can affect a skydiver falling back to earth. These forces include:
Wind: Wind can affect the skydiver’s speed and direction of travel. A strong headwind can slow the skydiver down, while a strong tailwind can speed them up.
Thermal currents: Thermal currents are rising columns of warm air. Skydivers can use thermal currents to gain altitude.
Turbulence: Turbulence is caused by changes in the wind speed and direction. Turbulence can make it difficult for skydivers to control their flight.
### Conclusion
The forces of gravity and air resistance are the primary forces that affect a skydiver falling back to earth. The magnitude of these forces depends on a number of factors, including the skydiver’s weight, surface area, and speed. The terminal velocity of a skydiver is the speed at which the force of air resistance is equal to the force of gravity. In addition to gravity and air resistance, there are a number of other forces that can affect a skydiver falling back to earth, including wind, thermal currents, and turbulence.