Calculating Force to Submerge 5 kg Object in Water

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SUMMARY

The force required to submerge a 5 kg object in water, which displaces 10 kg of water, is 49 N. This conclusion is derived from calculating the buoyant force, which equals the weight of the displaced water (10 kg * 9.81 m/s² = 98.1 N). To submerge the object, the applied force must counteract both the buoyant force and the weight of the object itself. Therefore, the net force required is 49 N, accounting for the downward force exerted by the object.

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Homework Statement



A 5-kg object displaces 10 kg of water. What is the force required to submerge the object?

a. 24 N

b. 147 N

c. 98 N

*d. 49 N

Homework Equations



Buoyant Force = Weight of the Water displaced

The Attempt at a Solution



Weight of the Water displaced=10kg*9.81m/s^2=98.1N

If the buoyant force is 98.1N an equal or greater force must be applied to submerge the object.

The answer key says its 49N...why?
 
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You are forgetting about the weight of the object. If you draw a free body diagram and apply all the forces, it becomes obvious.
 
Ohh right the object pushed downward too
 

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