A block of volume 3 x 105m3 and density 2.5 x 103 kg m-3 is suspended from a spring balance with \(\frac{2}{3}\) of its volume immersed in a liquid of density 900 kg m-3. Determine the reading of the spring balance [g = 10ms-2]
A. 0.18N B. 0.57N C. 0.75n D. 0.93N
Correct Answer: B
Explanation
Volume immersed solid = 3 x 105 x \(\frac{2}{3}\) = 2 x 105m3 Mass of liquid displaced = ev = 2 x 105 x 900 = 18 x 107 kg Upthrust = 18 x 107 x 10 = 7.8 x 109N Mass of solid = ev = 2.5 x 103 x 105 = 7.5 x 108 Weight of solid = 7.5 x 108 x10 = 7.8 x 109 Reading = 0.75 - 0.18 = 0.57N
