Question

A spring balance reads 10 kgs when a bucket of water is suspended from a tour

Answer 1

Question should be "A spring balance reads 10 kg when a bucket of water is suspended from it. What is the reading on the spring balance when

(i) an ice cube of mass 1.5 kg is put into the bucket.

(ii) an iron piece of mass 7.8 kg suspended by another string is immersed with half its volume inside the water in the bucket? Relative density of iron = 7.8.", and it's answer is

(I)Reading on spring balance when ice of mass 1.5 kg is put in bucket = 11.5 kg

(ii) Mass of iron piece = 7.8 kg

Density = Mass × Volume

Volume of iron piece  7.8/7.8×10 = 10^-3 kg^3

Volume of iron immersed = 10^-3/2

Mass of water displaced by iron piece = 10^-3/2 × 10^3 = 0.5 kg

Now, reading in spring balance = 10+0.5 = 10.5kg