Work done on moving a submerged object

In summary, the conversation discusses the process of calculating the buoyant force and tension in a tank, as well as determining the work done by tension. The buoyant force was first calculated using the given values of density, gravity, and volume. Then, the force of gravity acting on the tank was determined. Finally, the tension was calculated using the formula for net force and was found to be 9751. The person also mentions potential confusion about the work done by tension and expresses concern about the missing units.
  • #1
Murray Inglis
2
0
Homework Statement
A 5.00 kg air-filled, sealed, rigid float tank that has a volume of 1.00 m3
is pulled 50.4 m
down to the seafloor in order to assist in lifting a sunken object. A diver standing on the
seafloor cranks a winch to pull the tank down.
How much work is required to pull the tank down? (You may safely ignore the mass
in the air tank and the mass of the winch rope.)
Relevant Equations
Fb = p(rho)Vg
I first worked out the buoyant force using rho = 1000, g = 9.8 and V = 1. (this gives Fb = 9800)
I then worked out Fg of the tank (5 x 9.8 = 49)
Then I used Fnet = Fb - Fg - T = 0 to work out tension as 9751.
I thought the work done would be the work done by tension (9751 x 50.4), but I'm not sure if this works.
 

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  • #2
Murray Inglis said:
I thought the work done would be the work done by tension (9751 x 50.4), but I'm not sure if this works.
Sounds good to me.
 
  • #3
Doc Al said:
Sounds good to me.
Oh great, thanks. It was a 7 mark question so it just felt like I was missing something.
 
  • #4
Murray Inglis said:
Oh great, thanks. It was a 7 mark question so it just felt like I was missing something.
You are missing the units next to the numbers you provided. If I were scoring this, I would subtract at least 1 mark for this.
 

1. What is the definition of work done on a moving submerged object?

The work done on a moving submerged object is the amount of energy transferred to the object as it moves through a fluid.

2. How is the work done on a submerged object calculated?

The work done on a submerged object is calculated by multiplying the force exerted on the object by the distance it moves in the direction of the force.

3. What factors affect the amount of work done on a submerged object?

The amount of work done on a submerged object is affected by the force exerted on the object, the distance it moves, and the density of the fluid it is moving through.

4. Can the work done on a submerged object be negative?

Yes, the work done on a submerged object can be negative if the force and the direction of motion are in opposite directions. This means that the object is losing energy as it moves through the fluid.

5. How is the work done on a submerged object related to its speed?

The work done on a submerged object is directly proportional to its speed. This means that as the object's speed increases, the amount of work done on it also increases.

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