Advertisements
Advertisements
Question
A test tube loaded with lead shots weighs 25 gf and floats upto the mark X in water. When the test tube is made to float in brine solution, it needs 5 gf more of lead shots to float upto level X. Find the relative density of brine solution.
Advertisements
Solution
When test tube floats is water:
Weight of test tube = 25 gf
By law of floatation
Weight of water displaced = Weight of test tube = 25 gf
When test tube floats in a brine solution, it needs 5 gf more of lead shots to float up to same level as in water.
Weight of test tube = 25 + 5 = 30 gf
By law of floatation :
Weight of brine solution displaced = Weight of test tube = 30 gf As, volume of brine solution displaced = Volume of water displaced
∴ R.D. of brine solution = `"Weight of brine solution displaced"/"Weight of water displaced"`
`= 30/25 = 1.2`
APPEARS IN
RELATED QUESTIONS
A body is held immersed in a liquid. (i) Name the two forces acting on the body and draw a diagram to show these forces. (ii) State how the magnitudes of two forces mentioned in part (i) determine whether the body will float or sink in liquid when it is released. (iii) What is the net force on the body if it (a) sinks and (b) floats?
A block of wood is so loaded that it just floats in water at room temperature. What change will occur in the state of floatation, if
(a) Some salt is added to water, (b) Water is heated?
Give reasons.
A body of volume V and density ρs , floats with volume v inside a liquid of density ρL. Show that `"v"/V = ρ_s/ρ_L` .
A body of weight W is floating in a liquid. Its apparent weight will be
Name an instrument based on this principle. State two uses of the instrument that you describe.
Explain the following:
An egg sinks in fresh water but floats in a strong solution of salt.
Explain the following:
A hydrometer is made heavy near the bottom.
If you put one ice cube in a glass of water and another in a glass of alcohol, what would you observe? Explain your observations.
Why do petroleum-based products float on the surface of the water?
Name different types of Hydrometers with their applications.
