A block of material of volume 2 X 1O-5m3 and density 2.5 x 10-3 kgm-3 is suspended from a spring balance with half volume of the block immersed in water. What is the reading of the spring balance? (Density of water =1.0x103 kg m-3 g = 10 ms-2).
A. 0.10N B. 0.25N C. 0.30N D. 0.40N E. 0.50N
Correct Answer: D
Explanation
Weight of object = mg = pvg = 2.5 x 103 x 2 x 10-5 x 10 = 0.5N; Upthrust = weight of displaced fluid = pvg water = 1.0 x 103 x 2 x 10-5/2 x 10 = 0.1N
