Question

please help me
it is a physics question​

Answer 1

Answer:

Upthrust = ( V×ρw  - m )×g  ...............(1)

where V is displaced volume of water, ρw is water density, m is mass of solid and g is acceleration due to gravity

 

if we substitute vales for hollow ball-A, we get,  (15×10-6 ×1000 - 12×10-3)×9.8 = 3×10-3 ×9.8 = 29.4×10-3 N  

 

volume of solid ball-B = 12×10-3 / 7800  = 1.54 × 10-6 m3

 

Hence upthrust for ball-B = (1.54×10-6× 1000 - 12×10-3 )×9.8 = -10.46×10-3 × 9.8 = -103 ×10-3 N

 

since ball-B is giving negative upthrust, ball-B will sink.