JEE Main20204 Sep 2020Morning ShiftPhysicsMechanical Properties of FluidsActual
A air bubble of radius 1 cm in water has an upward acceleration of 9.8 cms – 2 . The density of water is 1 gm cm – 3 and water offers negligible drag force on the bubble. The mass of the bubble is g = 980 cm / s 2 .
Options
- A4.51  gm
- B3 . 15  gm
- C4.15  gm
- D1.52   gm
Correct answer
C. 4.15  gm
Step-by-step solution
F b − mg = ma F b = m g + a = 4 3 πr 3 ρg = m g + a m = 4 3 π 1 g = m 980 + 9 .8 m = 4 . 15