NIOS Class 10 Science Activity 11.6 Gravitation

In this activity, we will understand the magnitude of the buoyant force experienced by an object when it is immersed in the fluid and find the answer to the following questions:

    1.  Do all objects in a given fluid experience the same buoyant force?

   2. Is the buoyant force not same for all fluids for a given object?

   3. What is the magnitude of the buoyant force experienced by an object?

 

NIOS Class 10 Science and Technology (212) Project File

This activity is based on the NIOS Class 10 science and technology (212) Chapter 11- Gravitation, Module 3- Moving Things.

Determining Buoyant Force Using a Spring Balance

Aim

To observe the effect of buoyant force on a stone

Materials Required

   1.   Piece of stone

   2.  Spring balance

   3. Thread

   4. Container filled with water

Procedure

 We take a piece of stone and suspend it from a spring balance with the help of a thread. The reading of the spring balance gives the weight of the stone in air.

 Now we slowly dip the stone into water and continue to notice the reading.

Observation

We observe that:

   1.  The weight of the stone suspended in the air is maximum.

   2. The reading of the spring balance decreases when the stone is gradually dipped into water.

   3. The reading remains constant when the stone reaches the bottom of the container.

Explanation

When the stone is immersed in water, the decrease in the reading of the spring balance indicates that an upward force is acting on the stone.

 This upward force is known as the Buoyant force of upthrust. The magnitude of the buoyant force is equal to the weight of the displaced water.

Archimedes discovered this principle on the basis of this experiment: When a body is immersed fully or partially in a fluid, it experiences an upward force that is equal to the weight of the fluid displaced by it.

The magnitude of the buoyant force depends upon:

   1.  Density of the fluid

    2. Volume of the body immersed in the fluid

Conclusion

We can conclude that the buoyant force experienced by the object in the fluid is equal to the weight of the fluid displaced, and this is Archimedes’ principle.

   

   All Activities Solutions of Gravitation

    1.  Activity 11.1 Solutions

    2. Activity 11.2 Solutions

    3. Activity 11.3 Solutions

    4. Activity 11.4 Solutions

    5. Activity 11.5 Solutions

    6. Activity 11.6 Solutions

Frequently Asked Questions

   1. What is buoyant force?

Answer – The upward force exerted by a fluid on an object immersed in it is called the buoyant force.

   2. Does the actual weight of an object change in water?

Answer – No, the actual weight of the object does not change in water or in any liquid.

   3. On what factors does the buoyant force depend?

Answer – The buoyant force depends on (i) the volume of displaced fluid, (ii) the Density of the fluid

   

   4. Which principle does the activity 11.6 explain?

Answer – Archimedes’s principle

   5. Do all fluids exert the same buoyant force on the same object?

Answer – No, different fluids do not exert the same buoyant force on the same object because of different densities.