Question

a body weighs 100newtons and 80newtons when submerged in water.calculate the upthrust action on the body
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Answer 1

Answer:

20 N

Explanation:

In air, the normal force is equal to the weight.

∑F = ma

N − mg = 0

N = mg

Submerged in water, the normal force is equal to the weight minus the buoyant force:

∑F = ma

B + N − mg = 0

N = mg − B

Plugging in values:

80 N = 100 N − B

B = 20 N