$(a)$ Name the two factors on which the buoyant force depends.
$(b)$ State the relationship between the buoyant force on an object and the weight of the liquid displaced by it.

Raman along with his family visited the Dead Sea. There,his father observed a lady lying on her back in the sea and reading a newspaper. This astonished Raman's father,who thought the lady might be practicing black magic. Raman explained to his father why the lady was not drowning.
$(a)$ What,according to you,is the reason the lady is not drowning in the Dead Sea?
$(b)$ What value is exhibited by Raman?

You have a bag of cotton and an iron bar,each indicating a mass of $100\, kg$ when measured on a weighing machine. In reality,one is heavier than the other. Can you say which one is heavier and why?

The volume of $50\, g$ of a substance is $20\, cm^3$. If the density of water is $1\, g\, cm^{-3}$,will the substance float or sink?

Gautam visited a fair along with his classmates. There he found that a hawker was selling balloons filled with helium gas. His teacher told the students that the balloons will rise in the sky and then stop after some distance. Gautam questioned his teacher as to why the balloons would stop. He started arguing with his teacher that the balloons would rise indefinitely. His teacher got irritated with him. Just then,Gautam's friend Avdesh took him aside and explained to him that the teacher was correct. The explanation given by Avdesh satisfied Gautam.
$(a)$ Why will the balloon stop after rising to a certain height?
$(b)$ What values are shown by Avdesh and Gautam?

What do you mean by buoyancy?