An object of volume 400cm³ and 2.5gcm‾³ is suspended from a spring balance with half its volume immersed in water. Determine the reading on the spring balance. (Density of water = 1gcm‾³)

A. 1200g
B. 1000g
C. 800g
D. 400g

Correct Answer: Option C

C. 800g

Explanation

Mass = density x volume

400 x 2.5 = 1000g

Loss in mass = volume x density

= 400/2 x 1 = 200g

Reading on spring balance = 1000 – 200g = 800g