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Mayank1444
@mayank1444
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Joined: Oct 11, 2021
Last seen: Nov 14, 2021
Topics: 0 / Replies: 2157
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Answer to: A beaker full of water is suspended from a spring balance. Will the reading of the balance change: (a) if a cork is placed in water? (b) if a piece of heavy metal is placed in it? Give reasons for your answer.

(a) The reading of spring balance will not change if a cork is placed in water because cork, being lighter than water, floats in water. (b) The rea...

4 years ago
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Answer to: If a fresh egg is put into a beaker filled with water, it sinks. On dissolving a lot of salt in the water, the egg begins to rise and then floats. Why?

When a lot of salt is dissolved in water, then the density of salt solution becomes much more than pure water. Due to its much higher density, the sal...

4 years ago
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Answer to: Giving reasons state the reading on a spring balance when it is attached to a floating block of wood which weights 50 g in air.

The reading on spring balance will be zero. This is because the weight of floating block of wood is fully supported by the liquid in which it is float...

4 years ago
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Answer to: A body floats in kerosene of density 0.8 x 10^3 kg/m^3 up to a certain mark. If the same body is placed in water of density

The body will sink less in water. This is because the density of water is more than that of kerosene due to which water will exert a greater upward bu...

4 years ago
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Answer to: Two different bodies are completely immersed in water and undergo the same loss in weight. Is it necessary that their weights in air should also be the same? Explain.

No, it is not necessary that their weights in air should also be the same. This is because the two bodies have undergone the same loss in weight on co...

4 years ago
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Answer to: If two equal weights of unequal volumes are balanced in air, what will happen when they are completely dipped in water? Why?

The two equal weights of unequal volumes which are balanced in air, will get imbalanced when they are completely dipped in water because due to their ...

4 years ago
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Answer to: An elephant weighing 40,000 N stands on one foot of area 1000 cm^2 whereas a girl weighing 400 N is standing on one ‘stiletto’ heel of area 1 cm^2.

Weight of elephant = 40000N Area of one foot = 1000 cm2 = 1000 x 10-4 m2 Weight of girl = 400N Area of heel of girl = 1 cm2 = 1 x 10-4 m2 ...

4 years ago
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Answer to: How does a boat float in water? (b) A piece of steel has a volume of 12 cm^3, and a mass of 96 g. What is its density:

(a) A floating boat displaces water equal to its own weight. This displaced water exerts buoyant force to balance the weight of boat and keep it afloa...

4 years ago
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Answer to: What are fluids? Name two common fluids. (b) State Archimedes’ principle. (c) When does an object float or sink when placed on the surface of a liquid?

(a) Those substances which can flow easily are called fluids. All the liquid and gases are fluids, like water, air etc. (b) Archimedes’ Principle :...

4 years ago
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Answer to: Define pressure. (b) What is the relation between pressure, force and area? (c) Calculate the pressure when a force of 200 N is exerted on an area of:

(a) Pressure is the force acting perpendicularly on a unit area of the object. (b) Pressure = (c) (i) Pressure on an area of 10 m2 Force = 200 ...

4 years ago
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Answer to: State the principle of flotation. (b) A floating boat displaces water weighing 6000 newtons. (i) What is the buoyant force on the boat? (ii) What is the weight of the boat?

(a) According to the principle of floatation: An object will float in a liquid if the weight of object is equal to the weight of liquid displaced by i...

4 years ago
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Answer to: Define buoyant force. Name two factors on which buoyant force depends. (b) What is the cause of buoyant force? (c) When a boat is partially immersed in water, it displaces 600 kg of water.

(a) The upward force acting on an object immersed in a liquid is called buoyant force. Factors affecting buoyant force: (i) Volume of object imm...

4 years ago
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Answer to: Write down an equation that defines density. (b) 5 kg of material A occupies 20 cm^3 whereas 20 kg of material B occupy 90 cm^3. Which has the greater density A or B?

(a) Density of substance = (b) For material A Mass = 5kg Volume = 20 cm3 = 20 x 10-6 m3 Density of material A = = 0.25 x 106 kg...

4 years ago
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Answer to: An object weighs 500 grams in air. This object is then fully immersed in water. State whether it will weigh less in water or more in water. Give reason for your answer.

The object will weigh less in water because an upward force (buoyant force) equal to the weight of water displaced acts on the object when immersed in...

4 years ago
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Answer to: Calculate the density of an object of volume 3 m^3 and mass 9 kg. State whether this object will float or sink in water. Give reason for your answer.

Volume = 3 m3 Mass = 9 kg Density of substance = Density of substance = = 3 kg/m3 And density of water = 1000 kg/m3 The object will float ...

4 years ago
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Answer to: A girl is wearing a pair of flat shoes. She weighs 550 N. The area of contact of one shoe with the ground is 160 cm^2.

Force, F = 550 N Area of contact of one shoe = 160 cm2 = 160 x 10-4 m2 Area of contact with two shoes =160 x 2 = 320 cm2 = 320 x 10-4 m2 (...

4 years ago
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Answer to: A pressure of 10 Pa acts on an area of 3.0 m^2. What is the force acting on the area? What force will be exerted by the application of same pressure if the area is made one-third?

If the area is made one-third i.e. 1 m2, then the force would be Pressure = Force = Area x Pressure = 3 x 10 = 30 N If the area is made one...

4 years ago
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Answer to: Why do camels have large flat feet?

Camels have large flat feet so that there is a greater area in contact with the sand which produces less pressure on the sand and the camels can move ...

4 years ago
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