Please Help!!! How can I quantitatively test the model for drag force. I can use
ID: 1474811 • Letter: P
Question
Please Help!!! How can I quantitatively test the model for drag force. I can use balloon, yellow ball, air, meter stick, string, timing device, motion detector, digital balance, computer with logger pro , graduated cylinder, beaker, water, ring stand and clamp.
1- what type of expermint is it
these are the resorces I have and I have no idea where to begen. any help would be greatly appreciated!!!
Resources
The following is a sophisticated model for the drag force that a fluid exerts on a sphere moving through it.
When objects move through a fluid like air or water (both liquids and gases are considered “fluids” in this context), the fluid exerts a friction-like retarding force on the object, called the drag force. This drag force is due to the viscosity of the fluid and to turbulence in the fluid caused by the movement of the object through it.
The drag force depends in a complex way upon the velocity of the object relative to the fluid (v ), the density of the fluid ( ), the cross-sectional area of the object ( A ), and the drag coefficient of the object ( D C ). A mathematical model for the drag force in terms of the just mentioned physical quantities is
FD = ½ CD Av2
Just for clarification, the cross-sectional area is the area of the shape the object looks like if it were heading directly towards you. (A cube heading towards you looks like a square, so it’s cross-sectional area would be A = s2 .) The drag coefficient is a number that describes how smoothly the object cuts through the fluid. The more “aerodynamic” theobject is, the lower its drag coefficient.
One phenomenon this model explains is why objects reach a “terminal velocity” when they are speeding up while moving through a fluid. For a ball being dropped through the air from a large altitude, as the ball speeds up the drag force exerted on it increases until it balances with all the other forces exerted on it, causing the acceleration of the ball to go to zero. It will have reached its terminal velocity.
Unfortunately, the drag coefficient ( D C ) is not a constant. It depends in a complex way on the density of the fluid ( ), the viscosity of the fluid ( ), the linear size of the object ( L ), and the velocity of the object relative to the fluid ( v ). To describe all this, physicists use a quantity known as the ‘Reynolds number’
Re= vL/
Explanation / Answer
drag force or also says the force of air friction for a falling body increase with speed
a freely falling object reaches a velocity at which force
of the air friction is equal and opposite to the gravitational force
at this point object will not accelarate
because its velocity is constant
then this speed is called as terminal velocity.
here with given equipement like balloon,
yellow ball, air, meter stick, string, timing device,
motion detector, digital balance, computer with logger pro ,
graduated cylinder, beaker, water, ring stand and clamp can go for the experiment
with using a formula FD = 1 / 2 CD A v2
as given information CD is not constant,
It depends in a complex way on the density of the fluid ( ),
the viscosity of the fluid ( ),
the linear size of the object ( L ),
and the velocity of the object relative to the fluid ( v ). with using ‘Reynolds number’
Re = v L /
by arranging the above mentioned equipement directly go for experimwnt.