Buoyancy (Weight of a barbell underwater)

AI Thread Summary
To determine the force a bodybuilder must exert to lift a 20-kg steel barbell underwater, the buoyant force is calculated using the formula Fb = Density x Volume x Gravity. The volume of the barbell is found to be 0.00254 m^3, leading to a buoyant force of approximately 24.92 N. The total force exerted by the bodybuilder must account for both the weight of the barbell and the buoyant force. Therefore, the required force is calculated as the weight of the barbell (20 kg) multiplied by the buoyant force, resulting in a total exertion of about 498.35 N. Understanding these calculations is crucial for bodybuilders training in aquatic environments.
wallace13
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A bodybuilder is holding a 20-kg steel barbell above her head. How much force would she have to exert if the barbell were lifted underwater?Fb= Density x Volume x Gravity
Density= mass/volume
7860= 20/ V

V= .00254 m^3
Fb= 1000 x .00245 x 9.81
Fb= 24.9174 N
 
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You've found the buoyant force, which is the force exerted by the water. But what's the force that she has to exert?
 
I've never done this type of problem wouldn't it just be mass*bouancy force 24.917 * 20 kg =498.35N
 

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