Why Does a Ship Float but a Stone Sinks ? :: āĻāĻžāĻšāĻžāĻ āĻāĻžāĻšā§ āĻāĻŋāĻ¨ā§āĻ¤ā§ āĻļāĻŋāĻ˛ āĻāĻŋāĻ¯āĻŧ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧ ?
Why Does a Ship Float but a Stone Sinks ?
Floating and sinking depend on density and buoyant force. Water pushes upward on objects with a force called buoyancy. A ship is heavy but its hollow shape spreads mass over a large volume. This makes the ship's average density lower than water. A stone is compact and denser than water. So the ship floats while the stone sinks.
Words: i. Buoyant Force, ii. Shipm iii. Water, iv. Weight, v. Stone
Key Point: A ship floats because its overall density is lower than water, but a stone sinks because it is denser than water.
āĻāĻžāĻšāĻžāĻ āĻāĻžāĻšā§ āĻāĻŋāĻ¨ā§āĻ¤ā§ āĻļāĻŋāĻ˛ āĻāĻŋāĻ¯āĻŧ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧ ?
āĻāĻžāĻšāĻž āĻā§°ā§ āĻĄā§āĻŦ āĻ¯ā§ā§ąāĻž āĻāĻ¨āĻ¤ā§āĻŦ āĻā§°ā§ āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ā§° āĻāĻĒā§°āĻ¤ āĻ¨āĻŋā§°ā§āĻā§° āĻā§°ā§āĨ¤ āĻĒāĻžāĻ¨ā§āĻ¯āĻŧā§ āĻŦāĻ¸ā§āĻ¤ā§ā§° āĻāĻĒā§°āĻ¤ āĻāĻĒā§°āĻ˛ā§ āĻāĻāĻž āĻŦāĻ˛ āĻĒā§ā§°āĻ¯āĻŧā§āĻ āĻā§°ā§, āĻ¯āĻžāĻ āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ (Buoyancy) āĻŦā§āĻ˛āĻŋ āĻā§ā§ąāĻž āĻšāĻ¯āĻŧāĨ¤ āĻāĻžāĻšāĻžāĻ āĻāĻ§ā§ā§° āĻšāĻ˛ā§āĻ āĻāĻ¯āĻŧāĻžā§° āĻĢā§āĻāĻĒā§āĻ˛āĻž āĻāĻ āĻ¨ā§ āĻā§°āĻ āĻĄāĻžāĻā§° āĻāĻ¯āĻŧāĻ¤āĻ¨āĻ¤ āĻŦāĻŋāĻ¯āĻŧāĻĒāĻžāĻ āĻĻāĻŋāĻ¯āĻŧā§āĨ¤ āĻāĻ¯āĻŧāĻžā§° āĻĢāĻ˛āĻ¤ āĻāĻžāĻšāĻžāĻā§° āĻāĻĄāĻŧ āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻāĻŽ āĻšāĻ¯āĻŧāĨ¤ āĻļāĻŋāĻ˛ āĻāĻ¨ āĻā§°ā§ āĻ¸āĻā§āĻā§āĻāĻŋāĻ¤ āĻšā§ā§ąāĻž āĻŦāĻžāĻŦā§ āĻāĻ¯āĻŧāĻžā§° āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻŦā§āĻāĻŋāĨ¤ āĻ¸ā§āĻāĻŦāĻžāĻŦā§ āĻāĻžāĻšāĻžāĻ āĻāĻžāĻšā§ āĻāĻŋāĻ¨ā§āĻ¤ā§ āĻļāĻŋāĻ˛ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧāĨ¤
āĻļāĻŦā§āĻĻ: i. āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛, ii. āĻāĻžāĻšāĻžāĻ, iii. āĻĒāĻžāĻ¨ā§, iv. āĻāĻāĻ¨, v. āĻļāĻŋāĻ˛
āĻŽā§āĻā§āĻ¯ āĻāĻĨāĻž: āĻāĻžāĻšāĻžāĻ āĻāĻžāĻšā§ āĻāĻžā§°āĻŖ āĻāĻ¯āĻŧāĻžā§° āĻ¸āĻžāĻŽāĻā§ā§°āĻŋāĻ āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻāĻŽ, āĻāĻŋāĻ¨ā§āĻ¤ā§ āĻļāĻŋāĻ˛ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧ āĻāĻžā§°āĻŖ āĻāĻ¯āĻŧāĻžā§° āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻŦā§āĻāĻŋāĨ¤
==========================================================
MCQ on “Why Does a Ship Float but a Stone Sinks ?”
1. Floating and sinking depend on ______. āĻāĻžāĻšāĻž āĻā§°ā§ āĻĄā§āĻŦ āĻ¯ā§ā§ąāĻž ______ ā§° āĻāĻĒā§°āĻ¤ āĻ¨āĻŋā§°ā§āĻā§° āĻā§°ā§āĨ¤
A. color only B. density and buoyant force C. sound D. light
Ans: B. density and buoyant force
Explanation: Density and buoyancy decide whether an object floats or sinks. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻ¨āĻ¤ā§āĻŦ āĻā§°ā§ āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ā§ āĻŦāĻ¸ā§āĻ¤ā§ āĻāĻžāĻšāĻŋāĻŦ āĻ¨ā§ āĻĄā§āĻŦāĻŋāĻŦ āĻ¸ā§āĻ¯āĻŧāĻž āĻ¨āĻŋā§°ā§āĻ§āĻžā§°āĻŖ āĻā§°ā§āĨ¤
2. What is the upward force of water called ? āĻĒāĻžāĻ¨ā§ā§° āĻāĻĒā§°āĻ˛ā§ āĻ ā§āĻ˛āĻŋ āĻĻāĻŋāĻ¯āĻŧāĻž āĻŦāĻ˛āĻ āĻāĻŋ āĻā§ā§ąāĻž āĻšāĻ¯āĻŧ ?
A. Gravity B. Friction C. Buoyant force D. Magnetism
Ans: C. Buoyant force
Explanation: Water pushes upward with buoyant force. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĒāĻžāĻ¨ā§āĻ¯āĻŧā§ āĻāĻĒā§°āĻ˛ā§ āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ āĻĒā§ā§°āĻ¯āĻŧā§āĻ āĻā§°ā§āĨ¤
3. Why can a ship float on water ? āĻāĻžāĻšāĻžāĻ āĻĒāĻžāĻ¨ā§āĻ¤ āĻāĻŋāĻ¯āĻŧ āĻāĻžāĻšāĻŋāĻŦ āĻĒāĻžā§°ā§ ?
A. It is made of paper B. Its average density is lower than water C. It has no weight D. It is very small
Ans: B. Its average density is lower than water
Explanation: The ship’s hollow shape lowers its average density. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž : āĻāĻžāĻšāĻžāĻā§° āĻĢā§āĻāĻĒā§āĻ˛āĻž āĻāĻ āĻ¨ā§ āĻāĻ¯āĻŧāĻžā§° āĻāĻĄāĻŧ āĻāĻ¨āĻ¤ā§āĻŦ āĻāĻŽāĻžāĻ¯āĻŧāĨ¤
4. What type of shape does a ship have ? āĻāĻžāĻšāĻžāĻā§° āĻā§āĻ¨ā§āĻā§ā§ąāĻž āĻāĻ āĻ¨ āĻĨāĻžāĻā§ ?
A. Solid shape B. Hollow shape C. Tiny shape D. Flat shape
Ans: B. Hollow shape
Explanation: A hollow shape spreads mass over a larger volume.
â āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž (āĻ
āĻ¸āĻŽā§āĻ¯āĻŧāĻž): āĻĢā§āĻāĻĒā§āĻ˛āĻž āĻāĻ āĻ¨ā§ āĻā§°āĻ āĻ
āĻ§āĻŋāĻ āĻāĻ¯āĻŧāĻ¤āĻ¨āĻ¤ āĻŦāĻŋāĻ¯āĻŧāĻĒāĻžāĻ āĻĻāĻŋāĻ¯āĻŧā§āĨ¤
5. Why does a stone sink in water ? āĻļāĻŋāĻ˛ āĻĒāĻžāĻ¨ā§āĻ¤ āĻāĻŋāĻ¯āĻŧ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧ ?
A. It is lighter than water B. It is hollow C. It is denser than water D. It contains air
Ans: C. It is denser than water
Explanation: Dense objects sink in water. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ āĻ§āĻŋāĻ āĻāĻ¨āĻ¤ā§āĻŦ āĻĨāĻāĻž āĻŦāĻ¸ā§āĻ¤ā§ āĻĒāĻžāĻ¨ā§āĻ¤ āĻĄā§āĻŦ āĻ¯āĻžāĻ¯āĻŧāĨ¤
6. Which object is compact and dense ? āĻā§āĻ¨ āĻŦāĻ¸ā§āĻ¤ā§ āĻ¸āĻā§āĻā§āĻāĻŋāĻ¤ āĻā§°ā§ āĻ āĻ§āĻŋāĻ āĻāĻ¨ ?
A. Ship B. Stone C. Balloon D. Sponge
Ans: B. Stone
Explanation: Stones are compact and have high density. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻļāĻŋāĻ˛ āĻ¸āĻā§āĻā§āĻāĻŋāĻ¤ āĻā§°ā§ āĻ āĻ§āĻŋāĻ āĻāĻ¨āĻ¤ā§āĻŦāĻ¯ā§āĻā§āĻ¤āĨ¤
7. What does buoyancy help an object do ? āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ā§ āĻŦāĻ¸ā§āĻ¤ā§āĻā§āĻ āĻāĻŋ āĻā§°āĻžāĻ¤ āĻ¸āĻšāĻžāĻ¯āĻŧ āĻā§°ā§ ?
A. Burn B. Float C. Melt D. Freeze
Ans: B. Float
Explanation: Buoyant force pushes objects upward in water. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻžāĻ¸āĻŽāĻžāĻ¨ āĻŦāĻ˛ā§ āĻŦāĻ¸ā§āĻ¤ā§āĻā§āĻ āĻĒāĻžāĻ¨ā§āĻ¤ āĻāĻĒā§°āĻ˛ā§ āĻ ā§āĻ˛ā§āĨ¤
8. A ship spreads its mass over a large ______. āĻāĻžāĻšāĻžāĻā§ āĻāĻ¯āĻŧāĻžā§° āĻā§° āĻĄāĻžāĻā§° ______ āĻ¤ āĻŦāĻŋāĻ¯āĻŧāĻĒāĻžāĻ āĻĻāĻŋāĻ¯āĻŧā§āĨ¤
A. color B. sound C. volume D. smell
Ans: C. volume
Explanation: Large volume lowers average density. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĄāĻžāĻā§° āĻāĻ¯āĻŧāĻ¤āĻ¨ā§ āĻāĻĄāĻŧ āĻāĻ¨āĻ¤ā§āĻŦ āĻāĻŽāĻžāĻ¯āĻŧāĨ¤
9. Which object has lower average density than water ? āĻā§āĻ¨ āĻŦāĻ¸ā§āĻ¤ā§ā§° āĻāĻĄāĻŧ āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻāĻŽ ?
A. Stone B. Iron block C. Ship D. Rock
Ans: C. Ship
Explanation: Ships float because their average density is lower than water. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻžāĻšāĻžāĻā§° āĻāĻĄāĻŧ āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻāĻŽ āĻšā§ā§ąāĻžā§° āĻŦāĻžāĻŦā§ āĻ āĻāĻžāĻšā§āĨ¤
10. Which statement is correct ? āĻā§āĻ¨ āĻāĻā§āĻ¤āĻŋāĻā§ āĻ¸āĻ āĻŋāĻ ?
A. All heavy objects sink B. Ships float because of low average density
C. Stones float on water D. Buoyant force pulls objects downward
Ans: B. Ships float because of low average density
Explanation: A ship floats because its overall density is less than water. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻžāĻšāĻžāĻā§° āĻ¸āĻžāĻŽāĻā§ā§°āĻŋāĻ āĻāĻ¨āĻ¤ā§āĻŦ āĻĒāĻžāĻ¨ā§āĻ¤āĻā§ āĻāĻŽ āĻšā§ā§ąāĻžā§° āĻŦāĻžāĻŦā§ āĻ āĻāĻžāĻšā§āĨ¤