# How To Find The Drag and Lift Force?

• mymachine
In summary, the conversation is about finding the drag and lift force for a block moving on air. The block has a rectangular cross-section and is moving from right to left. The area of the surface is denoted by "A" and has a depth of 10 m. There is some confusion about the illustration and the direction of motion. The conversation ends with a disagreement about the tone of the initial response.
mymachine
I don't understand how is drag and lift related to a sliding block?

jedishrfu said:
I don't understand how is drag and lift related to a sliding block?

It's not a sliding block.

It's moving on the air.

mymachine said:
How can I find the drag and lift force such as below illustration?

http://s4.postimage.org/sxmnflttp/dragillustration.png

Below is my calculation:

http://s4.postimage.org/ao75d6r0d/dragcalculation.png

mymachine said:
It's not a sliding block.

It's moving on the air.

Which block? There are two in the illustration. And which way is it moving? Where does this problem come from?

Perhaps the illustration is showing that the block has a rectangular cross-section? Then, perhaps the block is moving to the right, in which case the 2000 N is the drag force?

I have never ever seen an FBD like this for fluid/aero dynamics...

berkeman said:
Which block? There are two in the illustration. And which way is it moving? Where does this problem come from?

Two?

Wrong.

As you can see from the first image, the "A" is the area of the surface which its depth is 10 m.

The motion is from right to left.

The snout is at the front and the flat is at the back.

mymachine said:
Two?

Wrong.

As you can see from the first image, the "A" is the area of the surface which its depth is 10 m.

The motion is from right to left.

The snout is at the front and the flat is at the back.

Be nice, we're trying to help and you didn't provide enough information to begin with.

jedishrfu said:
Be nice, we're trying to help and you didn't provide enough information to begin with.

Am I that really not so nice?

I just telling that was wrong.

No other purpose.

mymachine said:
Am I that really not so nice?

I just telling that was wrong.

No other purpose.

Okay, but its considered harsh to say it that way.

Instead most people would say: No, there's only one box.

## What is drag force?

Drag force is the resistance force that acts on an object as it moves through a fluid, such as air or water. It is caused by the interaction between the object and the fluid molecules.

## What is lift force?

Lift force is the force that acts perpendicular to the direction of motion on an object as it moves through a fluid. It is generated by the difference in pressure between the top and bottom of the object, and is responsible for keeping an object in the air.

## How do you calculate drag force?

Drag force can be calculated using the equation Fd = 1/2 * ρ * v^2 * Cd * A, where ρ is the density of the fluid, v is the velocity of the object, Cd is the drag coefficient, and A is the reference area of the object.

## How do you calculate lift force?

Lift force can be calculated using the equation Fl = 1/2 * ρ * v^2 * Cl * A, where ρ is the density of the fluid, v is the velocity of the object, Cl is the lift coefficient, and A is the reference area of the object.

## What factors affect drag and lift force?

The factors that affect drag and lift force include the density and viscosity of the fluid, the velocity of the object, the shape and size of the object, and the roughness of the object's surface. Additionally, lift force is also affected by the angle of attack and the lift coefficient, while drag force is affected by the drag coefficient.

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