Answer:
3.73 m
Explanation:
1375 mm Hg corresponds to a pressure of 18693.264 kgf/m^2.
Dividing that by the density will give the depth allowed, which is the diameter of the sphere:
(18693.264 kgf/m^2)/(5010 kgf/m^3) ≈ 3.73 m
The sphere can be up to 3.73 m in diameter.
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1 kgf is the force produced by a 1 kg mass in Earth's gravity field, about 9.8 N.