What is Air resistance: Definition and 415 Discussions
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, drag force depends on velocity.Drag force is proportional to the velocity for a laminar flow and the squared velocity for a turbulent flow. Even though the ultimate cause of a drag is viscous friction, the turbulent drag is independent of viscosity.Drag forces always decrease fluid velocity relative to the solid object in the fluid's path.
So I was going through an ODEs textbook and in a section discussing physical problems, decided that it would be interesting to come up with the equations of motion using Lagrangian mechanics for the examples they posted. For the first example, a falling rock, this easily worked. The second...
Hello,
the other day i was playing pool, and i wondered about the following question: when a body is subject to air resistance, does it eventually get to zero speed? Or does it gradually slow down but never reaching 0 speed?
Excuse me if this question is nonsense, but when i heard about...
There are two objects, let's go with the classic cannon ball and football. These objects are both equal in size and shape but they obviously have different masses (the cannon ball being heavier). My question is, will these two objects fall and hit the ground at the same time if dropped from the...
Im getting stuck on a couple of the questions for my mechanics homework. Il put what I've done so far and hopefully someone can check I am doing it right n push me into the right direction for the rest.
"A grandfather clock has a simple pendulum...
I would like to derive the air resistance equation showed in the attached photo. A little while ago, I tried asking at a different forum, however, the users were very experienced and omitted several stages of the derivation, and thereby made the interpretation difficult as I am new to math, but...
Ok so if an electron is launched at a high speed such as 7 million m/s and it travels through air it would encounter resistance that would slow it down even though it is a subatomic particle. I am guessing that you would not be able to apply standard air resistance equations to figure out the...
Homework Statement
I'm attempting to solve the differential equation,
\frac{dv}{dt}=\frac{P}{mv}-\frac{1}{2m}C\rho Av^{2}
where P, \rho, m, A, C are constants.
The differential equation is used to approximate the velocity of a cyclist undergoing air resistance.
It's actually presented as a...
I have been unable to solve this problem featured in "Elementary Differential Equations" by Edwards and Penney. The problem is this: I do not know how to integrate the function, and get the desired result. I would very much appreciated any help and instructions on how to get the two air...
Basically I have an experiment which involves attaching circular discs of varying radius to a pendulum, monitoring how its amplitude varies with time.
In my write up I need to include an explanation of how air resistance causes a damped oscillation over time. So far I have written:
Air...
Homework Statement
A particle of mass m slides down an inclined plane under the influence of gravity. If the motion is resisted by a force f = kmv^2, show that the time required to move a distance d after starting from rest is
t = [arccosh(e^(kd))]/√(kgsin(θ)
where θ is the angle of...
Before I write anything, I want to apologize because I have no idea how to write equations on this website. This is my first post >.< Also, thank you for helping in advance!
Homework Statement
A baseball is thrown vertically up with speed vo and is subject to a quadratic drag with magnitude...
Homework Statement
Given: effects of drag for a free falling body are a= 9.81[1-(v^2)*10^-4] m/s^2
V0 = 0 m/s and the falling body is very very high
Find: the velocity after 5 seconds and the bodies terminal velocity as t -> infinity
Homework Equations
∫dv = ∫a dt...
Homework Statement
The Attempt at a Solution
I've solved part (a) by solving the differential equations in the x and y directions, but for the approximation maximum range part I'm slightly confused:
1. What does it mean by "assuming the correction with k ≠ 0 is small? I tried to...
Homework Statement
Here I have drawn for the following scenarios:
Linear Resistance FR = -k\vec{v}
a)Free-fall starting from rest, downwards as positive.
Now it gets trickier...
b)Free-fall starting from rest, upwards as positive.
My reasoning is as such:
Since the...
Homework Statement
A car is rolling down a hill, it has a velocity of 54.22m/sec at the bottom of the hill. When it reaches the bottom of the hill, a fan begins to blow on it causing a drag force of 250N. Also, the tires create a friction coefficient of .1. The car eventually stops due to...
Hi. Consider the basic eq for a falling body with air resistance
dv/dt=g-kv/m
I don't understand air resistance as a force, since it seems irreconcilable to the force equation F=ma. How is a force a function of velocity? I am also not sure how this equation makes sense in terms of...
Homework Statement
Terminal speed = 43 m s-1Homework Equations
Acceleration in y direction when ball falling down: ay = - g + \alphavvy
where \alpha = K/m
and v = (vx2 + vy2)^0.5The Attempt at a Solution
Putting ay = 0 as there is no acceleration when terminal speed occurs.
However, is vvy...
Homework Statement
Hello! This is my first time posting here but I have been viewing these forums for help in my physics class for a while. Lately I have been stuck on one single problem that I haven’t been able to find any help with anywhere online. Any who, here is the problem: a cat...
1. After dropping coffee filters, I have to derive or describe the relationships between air Resistance(R) and v or v^2, whichever is right, and draw a graph. I can find derivations on internet as long as I site.
I have time, v, height and acceleration, but no reference area. All the equations...
Homework Statement
Hi,
I have to model the velocity and displacement of different paper shapes assuming that air resistance, R is proportional to velocity, v.
I have also conducted an experiment, and the equation of the line
h = 1.532t - 0.366
Where h is the height the paper shape was dropped...
Homework Statement
A raindrop of mass 3.35x10-5 falls vertically at constant speed under the influence of gravity and air resistance. Model the drop as a particle. As it falls 100m, what is the work done on the raindrop. (a) by the gravitational force and (b) the air resistance...
Last semester I did a project for grade 12 physics where I had to account for air resistance in projectile motion. I just wanted to post my solution here and as I never found out the merit of the solution, my teacher said that it came out to around the right anser but he said he didn't...
Homework Statement
A ball of mass 0.9kg is shot from a slingshot at an angle of 60° from the ground. The slingshot is sitting 1m above the ground. The elasticity of the slingshot is k = 700N/m. Take gravity = 10m/s^2
Air resistance must be taken into account also. Use the formula D = (...
Hey all, me again. This time my question has to do with projectile motion with air resistance from a given height.
Homework Statement
A cannon is located on a cliff of height h. If the muzzle velocity of a projectile is v0, find the range of the projectile when the drag is proportional to the...
Hey guys, first time poster but I'm a physics major and probably going to stick around for a while to help people or get some help myself :P
Anyway, on to the problem!
Homework Statement
A particle is released from rest and falls under the influence of gravity. Find the relationship...
Homework Statement
A ball of mass 9N is shot from a slingshot at an angle of 60° from the ground. The slingshot is sitting 1m above the ground. The elasticity of the slingshot is k = 700N/m. Take gravity = 10m/s^2
Air resistance must be taken into account also. Use the formula D = (...
Homework Statement
"If a ball is thrown upward in presence of air resistance, would you expect the time during which it took to rise to be longer or shorter than the time it takes for it to fall. (use the principle of exaggeration)"
Homework Equations
The Attempt at a Solution...
Homework Statement
A particle is release 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) αv and (b) βv²
The Attempt at a Solution
Setting the origin at the...
Hi,
In a demonstration that was shown in class, two paper cups were dropped from different heights. The first was dropped from two meters and the other was dropped from one meter. Both landed on the ground at the same time.
Why is this so? Would it be reasonable to say that if I dropped one...
in free fall without air resistance what is the force that causes the constant acc? Is it the object weight ?
And in free fall with air resistance what is the applied force ? Is it the weight of the object and the resistive force is the air resistance? And the net force is the one that causes...
Homework Statement
Hi, I'm trying to determine g (very precisely) using a falling ball in non-vacuum. I'm using three laser beams (along the z-axis), they're detecting when the ball enters the beam and leaves it again. This will give me six different times. To only problem is that we don't know...
Hey guys, I am in the process of writing a program for pmotion with air resistance that is proportional to the velocity squared and I've hit a stump. In my program it simulates the path of the ball by changing the time and putting it into the equation and plotting it on a graph. My problem is...
Homework Statement
A small piece of Styrofoam packing material is dropped from a height of 2.00 m above the ground. Until it reaches terminal speed, the magnitude of its acceleration is given by a = -g + bv. After falling 0.500 m, the Styrofoam effectively reaches terminal speed, and then...
So, I have been thinking about this idea for a long time. I have heard that if you travel behind a semi-truck, then you drive within a pocket of stagnant air behind the truck and will end up using less gas because of this... My question is, if I attached a large piece of plywood in front of my...
I need some help doing very basic mathematical analysis (what would be expected of a Calculus 1 and current Physics 1 student) for my project about tank projectiles, anything to calculate something about their air resistance/air drag, yet everything I have found has either been too simple (drag...
Homework Statement
a ball with mass m is thrown up from the ground with a velocity v_0
the force due to Air resistance is: F=-bv
(there's also gravity)
find the velocity and distance with respect to time
The Attempt at a Solution
I think I got the velocity...
Homework Statement
An object weighting 100N is traveling vertically upward from the Earth in the absence of air resistance at a constant velocity of 5 m/s. What is the power required to keep the object in motion?
Homework Equations
P = ΔE/t and P = Fvcosθ
The Attempt at a Solution...
If I know the theoretical acc down is 9.8 and I have the actual acceleration to be 9.2, do I use 9.8-9.2 to find the air resistance force? Or do I use 9.2-9.8?
And then after that, do I multiply it by the mass? Or do I calculate both forces and then subtract them?
Homework Statement
Say there were 2 balls of different masses projected at the same angle and subjected to the same air resistance. Will the heavier ball reach a higher maximum vertical height than the smaller ball or vice versa?
This is for my school experiment for projectile motion. I...
Homework Statement
I need to develop an equation for the damping factor with respect to time for a pendulum that consists of a spherical mass attached to a string that is damped by air resistance.
Homework Equations
We are given that the curve fit for the drag coefficient is...
I feel like this does not necessarily fit the format of a homework problem perse, but I am not sure where else to ask, but—
I was doing a thought experiment of a trajectory with air resistance (Air-resistance being proportional to the velocity with some constant), and was thinking to solve it...
Homework Statement
A car with a flat front is accelerating in the horizontal direction so that an 80 kg person on the front face of the car stays in equilibrium. The coefficient of friction between the person and the surface of the car is .8. The resistance force by the air on the person is...
Homework Statement
Consider a projectile subject to air resistance. The drag force is F=-\hat{v} C v^{a} where C and a are constants and v=\dot{r}. Restrict the problem to 2-D and take y in the vertical direction. Take the magnitude of initial velocity to be v_{0} and the initial position to...
Hi, I am in need for some physics help regarding the effect of air resistance on projectile motion.
My question is "For a tennis ball stuck at an angle of 45 degrees to the horizontal at typical speed without spin, why does air resistance have a greater effect on the horizontal range of the...
A ball of mass m is released from rest at x=0. Air resistance is expressed as R = kv2 , where k is a positive constant and v denotes velocity.
Derive an expression for the speed in terms of the distance x that it has fallen.
Identify the terminal v.
I know I have to start with ma = mg -...
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...
1. Calculate the air resistance co-efficient of the ballonI trying to do my best because I have this equations in my notes Fd = k . v^2 and its says the force of air resistance is proportional to the square of the velocity of the object.
So I only now v^2 I think is my terminal velocity that is...
Homework Statement
A fire helicopter carries a 625 kg empty water bucket at the end of a cable 21.7 m long. As the aircraft flies back from a fire at a constant speed of 36.6 m/s, the cable makes an angle of 35.3° with respect to the vertical. Calculate the force of air resistance on the...
Homework Statement
Equation 2.33 gives the velocity of an object dropped from rest. At first, why v_{y} is small, air resistance should be unimportant and 2.33 should agree with the elementary result V_{y} = gt for free fall in a vacuum. Prove that this is the case. [HINT: remember the...