Air resistance Definition and 405 Threads

  1. H

    Rocket with Variable Mass and Air Resistance.

    Problem: A rocket is launched vertically upward. The rocket has a mass Mr and carries Mo of fuel. The fuel burns at a constant rate (ß) and leaves the rocket at speed Ve relative to the rocket. Assume constant gravity (9.8m/sec^2). There is an air resistance given by F(a) = -kV. Where V is the...
  2. 4

    Parabolic motion. air resistance?

    [b]1. a 150 pound person on a snowboard launches off a 45 degree angle jump at 12 feet per second. what is the peak hight, flight time, horizontal displacment, and vertical displacement. [b]3. i tryed to use kinimatic equations to determine all the variables but all were way off[WAY off]. i...
  3. E

    What is the work done by air resistance on a falling pilot?

    Homework Statement An airplane pilot fell 370 m after jumping without his parachute opening. He landed in a snowbank, creating a crater 1.1 m deep, but survived with only minor injuries. Assuming the pilot's mass was 80 kg and his terminal velocity was 50 m/s, estimate: (a) the work done by...
  4. A

    Is My Equation for Modelling Air Resistance in a Computer Game Accurate?

    Hi, I'm trying to model air resistance to try and predict where destroyer gun shells will land on an online computer game. I've tried quite a few things which have met with some success but are not accurate enough. I think however this time I might have found a better solution in the form of...
  5. R

    Ploting trajectory, including air resistance.

    I am trying to plot the trajectory of a projectile. I found formulas for finding the drag force, but it only gives me the drag force at an impossibly short interval of time, i need it to affect the trajectory of the projectile threw out it's path. The projectile is also affected by gravity. If...
  6. J

    What is the Distance a Ruler Falls Before Being Caught Without Warning?

    Homework Statement Human reaction time is usually about .20s. If your lab partner holds a ruler between your fingers and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it. (disregard air resistance g= 9.81 m/s^2) Homework Equations...
  7. M

    Calculating air resistance homework

    Homework Statement I'm currently working on a lab which involves swinging a bung in the horizontal plane (just like a conical pendulum), however I'm a bit stumped at finding air resistance. The variables we know are the radius, the centripetal force and the velocity of the bung. The...
  8. P

    Projectile Motion: Solving for Angle in the Absence of Air Resistance

    Hi guys, got a question and been trying to solve it for 2 days. the question is: In the absence of air resistance with what angle to a horizontal ground must an object be thrown from ground level so that it ravels a distance before landing equal to twice the maximum height ? I know...
  9. A

    Finding Force of Air resistance

    My class did a lab where we roll a cylinder down a ramp (the end of the ramp was at the edge of the table). We placed a photogate timer right at the position where the cylinder fell off the ramp, and a photogate timer right at the position where the cylinder hit the floor. The information...
  10. S

    Air Resistance and Gravitational Force

    If you jumped out a plane, you would begin speeding up as you fall downward. Eventually, due to wind resistance, your velocity would become constant with time. After this occurs, the wind resistance force’s magnitude is a.much smaller that the gravitational force acting on you. b.slightly...
  11. C

    Work QUICK: And Energy Problem Involving Air Resistance

    QUICK: Work And Energy Problem Involving Air Resistance a projectile mass of 0.750 kg is shot straight up with an intial speed of 18.0 m/s. (a) how high would it go if there were no friction? (b) if the projectile rises to a max height of only 11.8 m, determine the magnitude of the avg force...
  12. T

    Calculate Height of Steamboat Geyser in Yellowstone Park

    i know this has to do with air resistance but what is the equation for it so i could use it for this problem? The Steamboat Geyser in Yellowstone National Park, Wyoming is capable of shooting its hot water up from the ground with a speed of 48.0m/s. How high can this geyser shoot?
  13. R

    Air Resistance Force on 1.21 g Samara Falling at 1.1 m/s

    A 1.21 g samara--the winged fruit of a maple tree--falls toward the ground with a constant speed of 1.1 m/s What is the force of air resistance exerted on the samara? I know that F=ma I also know I have to account for 9.81 N for g. So by upward force am I looking for W? That would be 11.9N.
  14. S

    Calculating Work Done by Gravity and Air Resistance on a Falling Raindrop

    i am doing my hoem work and this question is confusing the hell outta me. A 4.35 * 10^-5kg raindrop falls vertically at constant speed under the influence of gravity and air resistance. After the drop has fallen 76m, what is the work done by gravity? After J is found for gravity, what is the...
  15. D

    Why Does Air Resistance Increase with Velocity in Freefall?

    Hey. Just a random though. Why does the force of air resistance increase for say...a freefalling body..as its velocity increases? Is it because it encounters more air particles to which it must overcome? Thanks, Dan.
  16. J

    Max Height of 6 kg Object with Air Resistance

    Hey there, I have been studying for my physics final coming up and I am constantly getting stuck on the stuff that we started at the beggining of the year. Such as this question: A 6 kg object is projected directly upwards with an initial speed of 15 m/s. This object experiences an average...
  17. J

    Projectile with air resistance

    A paticle of mass m is projected vertically upwards with speed U. The air resistance produces a retarding force mkv^2 , where k constant and v the speed of the particle. Find the greatest height reached by the particle. Determine the speed W with which the particle will return to the point of...
  18. G

    Initial Velocity for X displacement with air resistance

    I'm in a high school AP physics class but I suspect this question is considerably above the course level because I don't think it was intended to be a part of the project, so I'm not sure which forum to put it in. I would like to find the initial velocity required to launch a ping pong ball 25...
  19. F

    What is the relationship between velocity and air resistance?

    My maths teacher before we broke up for christmas asked the class to work out a simple model for air resistance for an object that is dropped given that the resistive force is proportional to the square of the velocity. I've spent about 10 minutes thinking about it, and this is what I came up...
  20. I

    How Does Air Resistance Affect Car Velocity?

    The Air Resistance of a car grows proportional to the square of the velocity. On a certain car is the air resistance 0,18kN when the velocity is 54km/h. So the problem is .. What is the air resistance when the velocity is 90 km/h? How high is the velocity when the air resistance is...
  21. P

    Free-falling body subject to air resistance

    If a free-falling body is not subject to air resistance, there is a linear relationship between v and t giving a line with constant slope (g) showing velocity increasing with time. If air resistance is taken into account, my guess is that acceleration will decrease until the terminal velocity...
  22. E

    Calculating Work Done by Air Resistance on a Thrown Ball

    Hi, I'm having problems with this question: ok first I determined what work that gravtity does which is m*g*(delta y) which in this case is -50 J I then used the CEW theorem equation using the velocities to find the total work done: (sigma W) = 1/2 m (v^2 (final) - v^2(initial)) which is...
  23. S

    Does Falling Rain Experience Air Resistance?

    So, here's the question: The speed of falling rain is the same 10m above ground as it is just before it hits the ground. What does this tell you about whether or not rain encounters air resistance? So here's my attempt: Since the speed of the falling rain is just the same 10m above ground...
  24. D

    Need help - projectile motion with air resistance

    Need urgent help -- projectile motion with air resistance Consider a projectile fired vertically in a constant gravitational field. For the same inital velocities, compare the times required for the projectile to reach its maximum height (a) for zero resisting force and (b) for a resisting...
  25. W

    Projectile motion with air resistance

    Ok, in this problem, only the y direction is dealt with Here is the problem You are standing on top of a building, 30 m above the ground. You throw a ball (m = 0.15 kg) with an initial velocity or 20 m/s (in the y direction). Air resistance is given as (1/30)*v (yet again only considering...
  26. D

    Mechanics: projectile motion with air resistance

    Hello All, I was recently intrigued by the site: http://www.lcse.umn.edu/specs/labs/catapult/ which sets about showing a computational solution to the problem of projectile motion with air resistance. I think the site is a great idea, and presented well, but it seems like some of the physics...
  27. P

    How can air resistance be incorporated into the falling particle equation?

    "A particle is relased from rest (y = 0)and falls under the influence of gravity and air resistance. Find the relationship between v and the distance of falling y when the air resistance is equal to a) av and b) Bv^2." I already solved part a by integrating dv/dt = -g - (a/m)(dy/dt) with...
  28. B

    Air Resistance & Horizontal Distance

    Air Resistance & Horizontal Distance Warning: Calculus Required This was a discussion question in my class's Young & Freedman University Physics book. Page 150, Chapter 5, #29. Q5-29 When a batted baseball (kicked football, whatever floats your boat, assume the initial vertical position...
  29. B

    Air Resistance & Wind Resistance Equations

    What equation represents the force of air resistance? Is it simply \vec F_{air} = c \vec v , or must the velocity be raised to a higher power? *Also, which equation represents wind resistance to an object, in the case where a wind is blowing relative to the ground ?
  30. B

    How does air resistance affect the trajectory of a projectile?

    Mathematically, how would air resistance affect trajectory? Suppose I shoot a cannonball with initial velocity v_0 at an angle of elevation \theta . Air resistance is a force antiparallel to velocity, represented by the equation (according to Barron's Physics C review book!) \vec F_{air} =...
  31. T

    Projectile motion + Air resistance equation?

    Take a look at this little web-progarm http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/ProjectileMotion/jarapplet.html I know that it uses the following equation to calculate the range of the projectile without air resistance R = (v^2 sin2(theta))/g R - Range v - intial...
  32. P

    Comparing Times of Flight in a Linear Air Resistance Model

    My question deals with times of flight under a linear model of air resistance. Let me describe the problem. Up problem: v' = -g - kv, x(0) = 0, v(0) = v_0 Down problem: v' = -g + kv, x(0) = h, v(0) = 0 Define T_{up} and h (max. height) by the Up problem: x(T_{up}) = h, v(T_{up}) = 0...
  33. B

    Calculating Air Resistance Work on a Thrown Ball

    let's say i have a 5kg ball and i throw it up with an initial V of 30m/s with air resistance of 25, how would i find the work done by air resistance on the way up and on the way down?
  34. S

    Bowling ball with air resistance problem

    A 22-cm-diameter bowling ball has a terminal speed of 85m/s. What is its mass. I get F=M(9.8). But then i don't know where to go from there or what to do with the 22 cm diameter :confused:
  35. T

    Calculating Air Resistance: How to Solve for Work Without Using Mass?

    Hey, While searching for a solution to a particular problem, I stumbled upon this forum; any help would be greatly appreciated. We're currently working on energy and power, and in spite of my past success with such problems, I couldn't solve this one: A volleyball is dropped from a...
  36. H

    Lack of air resistance VS lack of gravity

    a small question, on the moon, the small amount of gravity prevents sudden falling like on earth, however would the lack of gases allow somebody jumping on the moon a much faster falling speed than on earth, because they do not have resistance from the electrons in usual earthly gases.
  37. T

    How Does Air Resistance Affect Work Done on a Falling Raindrop?

    A 3.51 x 10^5 kg raindrop falls vertically at constant speed under the influence of gravity and air resistance. The acceleration of gravity is 9.8 m/s^2 : After the drop has fallen 115 m, what is the work done by air resistance? would it be opposite of that done by gravity which i found...
  38. O

    Does Air Resistance Increase with Speed Due to Collisions with Air Particles?

    I'm doing a data handling course work project. I've calculated various values for resistance and found that resistance increases as the speed of the body increases. I know that as the body is rolling very little of the force is friction, so most of it will be air resistance. i have an idea...
  39. $

    Air resistance Differential Equation Help

    Hi guys I need help solving the following differential equation for air resistance d^2s/dt^2 + R ds/dt = g Where g = gravity I presume and R = k/m where k = resistance constant Using my limited knowledge I think that the auxiliary equation for this is Y^2+ RY = 0 Y = 0 or R...
  40. $

    Modelling Air Resistance using Differential Equation

    hi , As a part of my project, i am modelling air resistance using a differential equation. For the write up, i need to discuss what assumptions i am making. I have the rest of the coursework sorted out. I have a few idea . Air resistance is presumed to be consistent. ( i.e no...
  41. B

    What is a typical constant for air resistance in relation to velocity?

    Hey I am just wondering about something, air Resistance is proportional to the velocity in some cases or velocity squared in others. dV/dt=kv what is a typical constant for k, i know it varies so let's just say a baseball at sea level(im sure you all can guess why I am asking this...
  42. P

    Does air resistance affect projectile motion?

    Hi all, If someone threw a ball vertically & we want to calculate the time needed to for the ball to return back to his hand taking into account air resistance, would it be different if we ignore air resistance?? When they derive the known laws for the maximum height, range & time, did...
  43. J

    Including air resistance in the calculation of falling objects

    Hello all, I have a sort of basic physics question for you all. I was wondering where I might look to get some simplified math to calculate the amounf of air resistance on a falling object if I know the shape, mass, and volume of the object. I'm doing a lab experiment where I have to drop...
  44. G

    Sky divers air resistance balances with their weight

    When a car is travlling at constant speed, we say that the forward force is equal to the frictional force. How is that possible? Shouldnt the car be stationary? Samething with sky divers, when the air resistance balances with their weight, how is it possible that they still move downwards...
  45. M

    How Do I Solve for Terminal Velocity Using Logs in My Air Resistance Lab?

    In this lab we dropped coffee filters from a given height (3 M) and want to determine their terminal velocity My problem is I don't know how to solve the log thing given. we have terminal velocity, V, in the formula Mg = bV^n which I change to V=(Mg/b)^(1/n) then to...
  46. M

    Air Resistance and projectile motion

    For projectile motion, how does one take air resistance into consideration? I have constructed a device to launch a projectile and I know how to deal with projectile motion without any air resistance, but I am unsure how I determine the range (the distance the marble/object will go) in the...
  47. K

    How Does Air Resistance Affect Jet Engine Performance?

    When a jet aircraft is flying at high speed doesn't the air impacting on the front of the engines compress the air before it gets into the compressor. And how fast does the combusted fuel leave an engine compared to the speed of airflow at the intake?
  48. M

    Deriving the Formula for Air Resistance and Viscous Drag Using Momentum

    How would one go about proving the formula D = 1/2C(rho)A(v^2) I have a suspicion momentum can be used to the show the derivation of this, right ?
  49. F

    Understanding Air Resistance Formula: Finding R, D, and p Variables

    the formula: R = (.5)DpAv^2 is used to determine how much air resistance (resistive force) is being placed on the object. R is the Resistive force. D is some dimensionless empirical quantity called the drag coefficient p is the density of air A is the cross-sectional area of the object...
  50. A

    Problems dealing with air resistance?

    Does anyone know how to solve for problems dealing with air resistance? For example: "The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W = 59500 N. The lift force L generated by the rotating blade makes an angle of...
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