Question

A ball weighing 4 kg of density 4000 kg m–3 is completely immersed in water of density 103 kg m–3 Find the force of buoyancy on it. (Given g = 10 m s–2.)

Answer 1

Mass of ball m = 4 kg Density of ball ρ = 4000 kg/m3 Volume of the ball V = m/ρ = 4/4000 m3 = 10-3 m3.Buoyant force or upthrust acting on the ball                     = Volume of water displaced x density of water x acceleration due to gravity                    = 10-3 m3 x 1000 kg/m3 x 9.8 m/s2                     = 9.8 kg. m/s2                    = 9.8 N.

therefore aprox(10N)

Answer 2

Given :

• Weight of ball = 4 kg

• Density of ball = 4000 kgm³

• Density of water= 103 kgm³

Need to find-

• Buoyant Force = ?

$\huge \mathtt{ \purple{SOLUTION:-}}$

$\implies \large{ F = ρgV}$

$\implies \large{F = 4/4000 × 10 × 103 = 10.3}$

So, buoyant force will be 10.3 N

Additional information:-

• p is written for 'pressure'.
• g is written for 'gravity'.
• V is written for 'change is velocity'.