What is Terminal velocity: Definition and 224 Discussions

Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid (air is the most common example). It occurs when the sum of the drag force (Fd) and the buoyancy is equal to the downward force of gravity (FG) acting on the object. Since the net force on the object is zero, the object has zero acceleration.In fluid dynamics, an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving.As the speed of an object increases, so does the drag force acting on it, which also depends on the substance it is passing through (for example air or water). At some speed, the drag or force of resistance will equal the gravitational pull on the object (buoyancy is considered below). At this point the object stops accelerating and continues falling at a constant speed called the terminal velocity (also called settling velocity). An object moving downward faster than the terminal velocity (for example because it was thrown downwards, it fell from a thinner part of the atmosphere, or it changed shape) will slow down until it reaches the terminal velocity. Drag depends on the projected area, here, the object's cross-section or silhouette in a horizontal plane. An object with a large projected area relative to its mass, such as a parachute, has a lower terminal velocity than one with a small projected area relative to its mass, such as a dart. In general, for the same shape and material, the terminal velocity of an object increases with size. This is because the downward force (weight) is proportional to the cube of the linear dimension, but the air resistance is approximately proportional to the cross-section area which increases only as the square of the linear dimension. For very small objects such as dust and mist, the terminal velocity is easily overcome by convection currents which prevent them from reaching the ground and hence they stay suspended in the air for indefinite periods. Air pollution and fog are examples of convection currents.

View More On Wikipedia.org
Recent contents Top users
  1. S

    Terminal Velocity: Max Velocity of Sub Atomic Particles

    is the maximum velocity acquired by sub atomic particle depends on its mass at rest
  2. C

    Weight in an elevator, at terminal velocity

    There's a discussion on reddit about an elevator not just in free fall, but at terminal velocity. I know that at the moment the elevator starts to fall, you would feel weightless. But does this hold true for terminal velocity as well? You have stopped accelerating, so you are experiencing a...
  3. E

    Terminal velocity of a rocket using dimensional analysis

    I started taking MIT's online physics course a couple of days ago, and since I have no physics background at all, I'm getting a bit confused with dimensional analysis. I'm trying to find a formula for the terminal velocity of a rocket, using air density ρ, gravity g, area of rocket affected by...
  4. G

    How to find terminal velocity from experimental data?

    Homework Statement So I have a set of data, velocity and time, of a falling object. So the question is: how can I get the value for the terminal speed? Homework Equations Since we're talking about terminal velocity an ecuation that descrives a Velocity vs time graph should be of the...
  5. M

    Linear drag in a liquid and terminal velocity

    Homework Statement An object moving in a liquid experiences a linear drag force: D =(bv, direction opposite the motion), where b is a constant called the drag coefficient. For a sphere of radius R, the drag constant can be computed as b = 6 pi n R, where n is the viscosity of the liquid...
  6. P

    Showing the Terminal Velocity equation is dimensionally correct.

    Hey guys, this is my er...first post. It's a first year university physics assignment that I'm having a bit of trouble with, any help will be rewarded with kind words!(bit of an empty gift, but it's all I have) Ok, here's the problem. The terminal velocity of a mass m, moving at ‘high speeds’...
  7. N

    Time taken to reach 90% of terminal velocity

    Homework Statement A 4.5 kg metal sphere is released in a fluid where k = 10.5 N s^2/m^s. How long does it take to reach 90% of its terminal velocity? Homework Equations Force of drag = kv^2, where k is the drag coefficient (I believe we're not considering buoyancy.) The Attempt at a Solution...
  8. I

    [objet falling] Air resistance / terminal velocity

    Homework Statement How would the graph of position vs. time for a single cone change under each of the following conditions? 1)the cone's mass was increased but its shape was kept the same. 2)the cone's mass was kept the same but its diameter was increased. 3)the cone fell through...
  9. S

    Terminal Velocity: The Energy Exchange with Surroundings

    This is a simple problem. Picture a ball dropping from great height such that it reaches terminal velocity. Its KE will not increase anymore, but mgh is still being lost. That energy has to go somewhere. 1) My friend and I believe the energy is lost to heating the surrounding fluid (what a...
  10. L

    Finding Terminal Velocity of a Balloon in Free Fall

    Hi everyone, I am doing a lab report about free fall, but I have to find the terminal velocity for the balloon, but I don't know if I can use the formula velocity = Distance / Time because I have 10 measures from free fall ( 0.2 m - 2 m) , and I have the time that it took to hit the ground...
  11. T

    Terminal velocity in a vacuum.

    I am curious if there is a terminal velocity for an object in free fall in a gravitational field based on the strength of that field. If I was falling to Earth and there was no atmosphere, and I had infinite time to fall(Meaning I'd never actually reach the surface) would the strength of Earth's...
  12. A

    Question to find speed at terminal velocity with mass and the air resistance

    On a recent drop, one of the parachutes holding a supply package didn’t open. If the mass of the package was 35 kg and the drag or air resistance factor was 0.8 kg/m, at what speed did the package reach terminal velocity? I am confused with this question mainly because of the unit used for...
  13. N

    Force vector on falling object to determine terminal velocity and to graph it

    Homework Statement k: constant v: velocity m: mass g: gravity Homework Equations Vt= √(2mg/CρA) F=ma The Attempt at a Solution part a. part b. I do not know if i am doing this right and i do not understand how to do part c. If you know how to do this please explain
  14. S

    Calculate the terminal velocity for a pollen grain

    Homework Statement Calculate the terminal velocity for a pollen grain falling through the air using the drag force equation. Assume the pollen grain has a diameter of 7 µm and a density of 0.3 g/cm3. Homework Equations Vterm= sq.rt of 2mg/pA Volume= 4/3pi*r^2 Density = m/v The...
  15. T

    Terminal Velocity In Glycerin 2.10 in Classical Mechanics

    Terminal Velocity In Glycerin 2.10 in "Classical Mechanics" Homework Statement For a steel ball bearing (diameter 2mm and density 7.8g/cm3) dropped in glycerin (density 1.3g/cm3 and viscosity 12 N s/m2 at STP) the dominant drag force is linear drag given by flin = 3*pi*n*D*v where D is the...
  16. J

    Time to reach terminal velocity

    Homework Statement What is a formula I can use to calculate time to reach terminal velocity? Must account for air resistance during the time it took to reach terminal velocity. Known: mass of object density of object radius of object magnitude of terminal velocity height of...
  17. M

    Time it takes to achieve terminal velocity?

    Homework Statement A 100kg skydiver has a terminal velocity of 58 m/s. Assuming air resistance of the skydiver is Fair=.3(v)2, how long will it take the skydiver to reach 58 m/s? gravity is 10 m/s2 in our class btw. Homework Equations Fair=.3(v)2 Fg=mgThe Attempt at a Solution I know the air...
  18. M

    Terminal velocity of 20 lb bowling ball at 40,000 feet

    I am looking for an estimated terminal velocity of a 20 lb bowling ball falling through 40,000 feet. I have looked at the equation, but am not sure what to use for the drag coefficient. Thanks for any help.
  19. davenn

    Understanding Terminal Velocity

    hi gang, from wikipedia... Mathematically, terminal velocity — without considering the buoyancy effects — is given by where Vt = terminal velocity, m = mass of the falling object, g = acceleration due to gravity, Cd = drag coefficient, ρ = density of the fluid through which the...
  20. B

    How Do You Calculate Terminal Velocity for a Wooden Sphere Falling Through Air?

    Homework Statement (a) Estimate the terminal speed of a wooden sphere (density 0.870 g/cm3) falling through air, if its radius is 8.00 cm and its drag coefficient is 0.500. (The density of air is 1.20 kg/m3.) (b) From what height would a freely falling object reach this speed in the absence...
  21. H

    Dimensional Analysis: Terminal Velocity

    Homework Statement The terminal velocity of a mass m, moving at 'high speeds' through a fluid of density ρ(kg m^-3), is given by v = sqrt(2mg/DρA) where A is the cross sectional area of the object (m^2) and D a dimensionless "drag coefficient". i) Show that equation is dimensionally...
  22. H

    PLEASE HELP in Deriving Terminal Velocity Equation

    PLEASE HELP! in Deriving Terminal Velocity Equation :) Homework Statement The terminal velocity of a mass m, moving at 'high speeds' through a fluid of density ρ(kg m^-3), is given by v = sqrt(2mg/DρA) where A is the cross sectional area of the object (m^2) and D a dimensionless "drag...
  23. PrincePhoenix

    Terminal velocity of spherical body.

    In our textbook, the equation for terminal velocity has been derived from Stokes' law and it comes down as follows, vt = (mg)/6(pi)(eta)r (r is the radius of the spherical body) then, by putting the value of 'm' from m=(rho)V [where V = 4/3 * (pi)r3] we get, vt = 2(rho)gr2 / 9...
  24. B

    My Terminal Velocity is Zero? (DE Question)

    [PLAIN]http://img204.imageshack.us/img204/11/60272414.png Hey guys, I'm stuck on this question, part b) I figured out a) and v(t) for V(0) = 0 ends up being mg - mge-kt/m k (Sorry, latex was being difficult) But then when I try to figure out the limit as...
  25. F

    Just a question on terminal velocity

    Homework Statement It is a definition that the terminal velocity is the same as constant velocity where the net force is 0 and therefore the acceleration is also 0 Here is what I don't get, why must the terminal velocity must such that it is constant? I know that to be "terminal" it means...
  26. S

    Terminal velocity of an object falling through a liquid

    I have a question regarding the terminal velocity of an object falling through a liquid. Now the speed will increase up to the terminal veloity in a given time. What I do not understand is in this calculation I'm performing (solving the equation of motion for the speed, when acceleration equals...
  27. A

    How Does a Spring Affect the Oscillation Frequency of a Ball in a Medium?

    Homework Statement The terminal speed of a freely falling ball in a medium is vt, free fall acceleration is g. In a differrent setting, the same ball, in the same medium, in the same gravity field is supported by a light elastic spring. In equilibrium, under the weight of the ball, the...
  28. K

    How Long Does It Take a Raindrop to Reach 63% of Its Terminal Velocity?

    Homework Statement The terminal velocity of a 2.8*10^{-5}kg raindrop is about 14 m/s. Determine the time required for such a drop, starting from rest, to reach 63 percent of terminal velocity.Homework Equations F_{g}-F_{D}=-bv The Attempt at a Solution F_{D}=1.96*10\exp{-5} mg-b*(0.63V_{T}) =...
  29. X

    Terminal Velocity given Time at which velocity is .5Vt

    Homework Statement A 9.00 kg object starting from rest falls through a viscous medium and experiences a resistive force R = -bv, where v is the velocity of the object. If the object reaches one-half its terminal speed in 5.93 s, (a) determine the terminal speed. Homework Equations...
  30. P

    Question about terminal velocity

    Homework Statement An object of weight W falls from rest subject to a frictional drag force bv^2. What maximum ("terminal") velocity will it approach if W = 4 N and b = 3 N∙ s2/m? The Attempt at a Solution I set W = Bv^2 and solved for v and got 1.15. I am not quite sure if...
  31. R

    Derive y as function of time in relation to terminal velocity

    Homework Statement Integrate v_{y} = v_{t} (1 - e^{-(\frac{k}{m})t})) to get y as a function of time. Homework Equations y = v_{t}(t - \frac{m}{k} (1 - e^{-(\frac{k}{m})t}))) is the solution. v_{t}=\frac{mg}{k} The Attempt at a Solution Well, when I integrate I get the following: y =...
  32. R

    Terminal velocity of falling drop with increasing mass

    I m solving the problem in which the drop is falling from some height and its size is increasing with the rate dm/dt=kMv where v is the velocity of the drop at that instant , so we have to find the terminal velocity of the drop gained due to air drag, The problem is that if the drop gains...
  33. G

    Difficult problem about eddy currents and terminal velocity

    Hey guy, Ive been recently investigating the phenomena of eddy currents, particularly that of a magnet falling down a copper tube. To the people who haven't seen it before, basically the magnet reaches terminal velocity in the copper tube extremely quickly, and takes a long time to leave the...
  34. M

    Terminal Velocity of a bobsled

    Homework Statement A bobsled has a frontal area of 0.86 m^2 and a coefficient of drag of 0.267. The air density is 1.043 kg/m^3. Total mass of the sled and the bobsled driver and pushers is 827 kg. Friction in the runners is negligible. The track slopes down at an angle of 0.078 radians. What...
  35. B

    Terminal Velocity of 100kg Parachutist Falling from 3000m

    Homework Statement A parachutist whose mass is 100kg drops from rest to an altitude of 3000m and falls under of gravity. Assume that the force due to to air resistance is proportional to the velocity of the parachutist , with the proportionality constant k1 = 20kg/s when the chute is closed...
  36. A

    Air Bubbles and Terminal Velocity-> why is my answer wrong? (all work shown)

    Air Bubbles and Terminal Velocity--> why is my answer wrong? (all work shown) Homework Statement Air bubbles of 1.0mm radius are rising from a scuba diver to the surface of the sea. Assume a water temp of 20C. a) If viscosity of water = 1.0 X 10-3 Pa.s, what is the terminal velocity of...
  37. P

    Viscous Drag and Terminal Velocity

    Homework Statement Droplets in a deodorant spray have mass of about (4x10^-12) kg and a radius of about 0.1mm. Estimate the terminal velocity of the droplets in Air of Viscosity (2x10^-5)Nsm^-2. Homework Equations Stoke's Law, F = 6pi rvu where r = radius, v = velocity and u = viscosity...
  38. D

    How Does Changing Drag Coefficient Affect Terminal Velocity in Downhill Skiing?

    Information: "In downhill speed skiing a skier is retarded by both the air drag force on the body and the kinetic frictional force on the skis. Suppose the slope angle is θ = 31.5°, the snow is dry snow with a coefficient of kinetic friction μk = 0.0400, the mass of the skier and equipment is m...
  39. A

    Does an Object Ever Truly Reach Terminal Velocity?

    We have the following formula for the velocity of an object moving in a fluid. v = vt -vte-kt/m. This formula shows that an object can never achieve terminal velocity but in the derivation of this formula given in "Fundamental of Physics" by H D Young and Freedman 10 edition we use the formula...
  40. Q

    Terminal velocity of a falling conducting ring

    Homework Statement A conducting ring with radius a and mass m is placed in a magnetic field at a height H above the origin of the reference frame. The plane of the ring is parallel to the ground, that is, the normal is directed along the z-axis. The electrical resistance per unit length of...
  41. A

    Terminal Velocity + Drag Force

    Homework Statement A sky diver of mass 79.5 kg jumps from a slow-moving aircraft and reaches a terminal speed of 53.0 m/s. (a) What is the acceleration of the sky diver when her speed is 30.0 m/s? What is the drag force on the diver when her speed is the following? (b) 53.0 m/s (answer in...
  42. U

    Terminal Velocity and Bouyancy - F = kv

    Homework Statement A rock of mass 0.400 kg is released from the surface and sinks in the ocean. As the rock descends it is acted upon by three forces: gravity, buoyancy, and drag. The buoyancy is an upward force equal to half its weight. Drag from the water can be modeled by F = kv...
  43. Z

    Solving the Mystery: Calculating Terminal Velocity

    Homework Statement Marks: 1 In a recent mystery, the hero saves himself by spreading out a windshield tarpaulin to reduce his terminal velocity. A skydiver of 75 kg mass has a terminal velocity of 60 m/s. If the hero has the same 75 kg mass, the same density as the sky diver, and a drag...
  44. L

    Stocke's law and terminal velocity

    Homework Statement Figure shows the motion of a rubber ball,of mass m,released (from rest),from the bottom of a pond.Explain the motion of the ball,with reference to its change in velocity and any other forces present,at points A,B,C,D and E Also comment on the path and velocity of the ball...
  45. P

    How Do Zero Gravity and Terminal Velocity Affect Passengers in an Aircraft?

    Hello everyone, I'm in great need of an expert answer and havn't been able to find much help at all, so I am hoping I have come to the best place. I have two questions regarding forces acting apon passengers in an aircraft. I would like to know how passengers would experience a zero...
  46. J

    What Factors Cause Miscalculations in Skydiver Terminal Velocity Estimates?

    good day all, out of sheer curiosity i tried to calculate what could be my terminal velocity in a skydive, since i will be diving in soon. using the terminal velocity formula: Vt = sqrt[ (2mg) / (pACd) where: Vt = terminal velocity m= mass g = acceleration due to gravity p = density of...
  47. A

    A reliable source for the terminal velocity of a tennis ball.

    Hi there, I've been looking over the internet for a while and I am looking to find the terminal velocity of a tennis ball from a reputable source. I am writing a paper for my college classical physics class. I found the terminal velocity for a tennis ball and it was about 9 m/s. I know this...
  48. P

    Distance it takes for terminal velocity

    Hi, i just wondered if it is possible by calculation to determine how far in a viscous liquid it would take for an object (sphere, ball bearing) to reach terminal velocity. I have to design an experiment to investigate Stokes law. Could i use suvat equations as it is constant acceleration? Thanks
  49. W

    Show that terminal velocity equals

    Homework Statement A conducting rectangular loop of Mass M and resistance R and length l and width w falls from rest into a magnetic field B as shown. During the time interval before the top edge of the loop reaches the field, the loop approaches the terminal speed v T . Show that...
  50. K

    How Do Terminal Velocity and Drag Influence an Object's Fall Through Fluids?

    hey,everyone,could you please explain to me the terms Terminal Velocity and Drag in detail,as my exams are coming up.
Back
Top