Falling question about terminal velocity

In summary, the group discusses the concept of terminal velocity and its relationship to free fall. They clarify that terminal velocity is not 9.81 m/s, but rather the acceleration due to gravity. They also explain that objects of different mass will fall at the same rate in a vacuum, but in the presence of air resistance, terminal velocity occurs when the force of gravity and air resistance are equal. This means that objects will continue to fall at a constant speed, determined by their size, shape, and mass. The group also mentions that in a demonstration, objects are chosen to minimize the effect of air resistance.
  • #1
Robertmunch
3
0
Hey guys I have a question.

Terminal velocity is 9.81mps correct? Which converts to basically 35kmph so does that mean hitting the ground from free fall after jumping out of an air plane would have the same effect as hitting a wall or something immobile and hard at 35kmph?

Thanks
 
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  • #2
Terminal velocity is not 9.81 m/s, it is the acceleration due to gravity that is 9.81 m/s^2. The terminal velocity acquired depends on the weight that is falling out of the airplane.
But in the case that there is some arbitary object with terminal velocity 9.81 m/s, the effect of having it fall to the ground and having it collide with an immobile wall, will be the same; the momentum imparted will be 9.81×mass in both cases.
 
  • #3
Oh I had a brain fart I guess. I thought I remembered a demonstration from physics class where the teach dropped 2 objects of different mass and they both hit the ground at the same time (obv the shape of the object would make a difference because of air resistance)
 
  • #4
Robertmunch said:
Oh I had a brain fart I guess. I thought I remembered a demonstration from physics class where the teach dropped 2 objects of different mass and they both hit the ground at the same time (obv the shape of the object would make a difference because of air resistance)
The experiment was to demonstrate that all objects (at the same distance above the Earth's surface) will fall at the same rate regardless of their mass, assuming that you can neglect air resistance. Objects are chosen so than the effect of air resistance is negligible over the fall.
Terminal velocity occurs when air resistance comes into play. It is determined by the the relationship between an object's size, shape and mass. Air resistance increases with velocity, so as the falling object accelerates, the air resistance increases, at some point the air resistance equals the force of gravity trying to accelerate the object, it has reached terminal velocity and just continues to fall at a set speed. Because of the above mentioned factors, terminal speeds for various objects can vary greatly. ( the terminal speed for a ball bearing will be greater than that of a feather even if they had the same mass).
 

1. What is terminal velocity?

Terminal velocity is the maximum speed an object can reach when falling through a fluid, such as air or water. It occurs when the force of gravity pulling the object down is balanced by the resistance of the fluid pushing against it.

2. How is terminal velocity calculated?

Terminal velocity is calculated using the formula v = √(2mg/ρAC), where v is the velocity, m is the mass of the object, g is the acceleration due to gravity, ρ is the density of the fluid, A is the cross-sectional area of the object, and C is the drag coefficient.

3. What factors can affect an object's terminal velocity?

The factors that can affect an object's terminal velocity include its mass, surface area, shape, density, and the density and viscosity of the fluid through which it is falling.

4. Can an object's terminal velocity change?

Yes, an object's terminal velocity can change if there are changes in the factors that affect it, such as changes in the density or viscosity of the fluid, or changes in the object's mass or surface area.

5. How does air resistance play a role in terminal velocity?

Air resistance, also known as drag, plays a crucial role in determining an object's terminal velocity. As an object falls, air resistance increases until it reaches a point where it is equal to the force of gravity, resulting in a constant velocity known as terminal velocity.

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