A body of mass 2 kg and volume 500 cm³ is completely immersed in water while suspended from a spring balance. Taking g = 10 m/s² and ρ(water) = 1000 kg/m³, the spring-balance reading is N N. Find N.
Physics · Fluid Mechanics · pascal law and buoyant force
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Question

A body of mass 2 kg and volume 500 cm³ is completely immersed in water while suspended from a spring balance. Taking g = 10 m/s² and ρ(water) = 1000 kg/m³, the spring-balance reading is N N. Find N.

Physics · Fluid Mechanics · pascal law and buoyant force

G1 Physics · Accepted Answer

Weight of the body: W = mg = 2×10 = 20 N. Volume: V = 500 cm³ = 5×10⁻⁴ m³. Buoyant force: B = ρ(water)Vg = 1000×5×10⁻⁴×10 = 5 N. Spring-balance reading is the tension: T = W−B = 20−5 = 15 N. Hence, N = 15.