Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions

(i)A block of mass 7 kg and volume 0.07 m^3 floats in a liquid of density 140 kg m^-3 Calculate volume of block above surface of liquid

(ii)A solid of density 5000 kg m^-3 weighs 0.5 kg in air It is completely immersed in liquid of density 8000 kg m^-3.Calculate apparent weight of solid in liquid
please tell me fast with detailed explanation of two questions.



This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Weight of block = buoyancy force = weight of liquid displaced

Volume of liquid displaced = V m³

7 * 10 Newtons = V * 140 * 10 Newtons

V = 0.05 m³

Volume above the surface of liquid = 0.07 - 0.05 = 0.02 m³

mass of solid = 0.5 kg       density = 5000 kg /m³

mass of liquid displaced by solid = volume of solid * density of liquid
              = (0.5/5, 000) * 8, 000 = 0.8 kg
Buoyancy force on solid = 0.8 kg * 10 m/s² = 8 Newtons

When the solid is completely immersed in the liquid, the buoyancy force is more than its own weight.  Hence, it will float immediately.  It looks as if its apparent weight is negative and is -3 Newtons or -0.3 kg.  ( 0.5g - 0.8g)

When it reaches the surface of the liquid, it will displace less volume of liquid such that buoyancy force = weight of solid. Then it floats.   Hence apparent weight = 0.

1 5 1
thankyou sir
looking for more questions
thankyou for suggesions
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts