What is Drag force: Definition and 165 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.
Homework Statement
A steel sphere in a tank of oil is given an initial velocity v = 2i (m/s) at the origin of the coordinate system shown (if you don't trust the attached image it is essenital). The radius of the sphere is 15 mm. The density of the steel is 8000 kg/m3 and the density of the...
Homework Statement
A gun is fired straight up. Assume a quadratic drag force.
Show
(upward motion) v^2 = Ae^{-2kx} - \frac{g}{k}
(downward motion) v^2 = g/k - Be^{2kx}
Homework Equations
The Attempt at a Solution
I can easily solve the integrals unfortunately I am having difficulty setting...
Hey,
I am trying to calculate the drag force on netting at supersonic speeds. currently I have been using the equation:
F = 1/2 (ρ V² Cd A)
I am having trouble applying it to netting due to the drag coefficiant, since i cannot find one for netting. Also all the examples I have seen for...
Homework Statement
A 710 kg car drives at a constant speed of 23 m/s. It is subject to a drag force of 500N. What power is required from the car’s engine to drive the car
a. on a level ground?
b. up a hill with a slope of 2.0 0?
Homework Equations
P=Fv
The Attempt at a...
Homework Statement
A baseball is thrown straight up. The drag force is proportional to v^{2}. In terms of g, what is the ball's acceleration when its speed is half its terminal speed and a) it is moving up? b) it is moving back down?
Homework Equations
\sum F=ma
mg + bv^{2}=ma - When...
Homework Statement
A particle of mass m is traveling along the x-axis with a constant horizontal velocity v0i. When the particle passes through the origin, it experiences a Drag Force which is proportional to the square of the particle's speed (Fd = - b/v^2i... drag coefficient b...
Prove this...
A particle of mass m is traveling along the x-axis with a constant horizontal velocity v0i. When the particle passes through the origin, it experiences a Drag Force which is proportional to the square of the particle's speed (Fd = - b/v^2i... drag coefficient b.
Questions
A)...
As most of you know, the drag force equation is Fd=1/2*p*Cd*V^2*Cd*Ac.
At terminal velocity, Fd equals weight. If you find the value of all the variables except Cd and V, you still won't have anything. But the terminal velocity equation is Vt= sqrrt of 2weight/p*Cd*Ac. So if V is terminal...
Hello everyone. I have researched from the internet that the drag force equation for projectile motion is either F= C p a v^2 or F= 0.5 C p a v^2. Which one is the correct one? The initial speed I am dealing with is about 20m/s. And what's the value for C for a normal tennis ball. Other sites...
Hello, please help me I have a question regarding drag force and Newton's law of motion.
This is quotes from online pdf files from University of Toronto Scarborough.
"the terminal velocity is F/b , where b is drag constant
Let’s solve the equation of motion and see how
this is reflected...
I have a question about a physics problem, this comes from Barger's Classical Mechanics: A boat is slowed by a drag force, F(v) and its velocity decreases according to the formula v=c^2(t-t_{1})^2 where c is a constant and t_{1} is the time at which it stops. Find the force F(v) as a function...
Can anyone Please help me on this. I am totally stuck at this question .
thanks...
...A sky diver of mass 80.0 (including parachute) jumps off a plane and begins her descent.
Throughout this problem use 9.80 for the magnitude of the acceleration due to gravity.
Q1.
At the...
The first part of a pretty involved, 8 part question on modelling drag force states: "A 0.142 kg ball has a terminal speed of 42.5 m/s. If a ball experiences a drag force of R=CV^2, what is the value of the constant, C?
I know this is a ridiculusly easy problem, but our text doesn't cover...
free fall with drag force
If the equation F=-bv^2 describes the drag force of an object...then the differential equation for the object's motion would be:
dv/dt= -g+bv/m
or is it...
dv/dt= g-bv/m
After solving the equation, should I get...
V=mg/b[1-e^(-bt/m)]
Also, does this...
Can anyone give me a relationship for the turbulent drag force on an object with a cross sectional area A and a speed v in a medium with density p please?
Thanks