What are the methods of preventing or reducing soil erosion?

Convert into mole.

(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.

Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?

Why is the atmosphere essential for life?

Why is the weight of an object on the moon 1/6th its weight on the earth?

What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?

Why are we normally advised to take bland and nourishing food when we are sick?

You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?

Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?

Abdul, while driving to school, computes the average speed for his trip to be 20 km h^-1. On his return trip along the same route, there is less traffic and the average speed is 40 km h^-1. What is the average speed for Abdul’s trip?

Explain the working and application of a sonar.

What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?

Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?

Why is the atmosphere essential for life?

Name A,B,C,D,E and F in the following diagram showing change in its state

What type of clothes should we wear in summer?

Abdul, while driving to school, computes the average speed for his trip to be 20 km h^-1. On his return trip along the same route, there is less traffic and the average speed is 40 km h^-1. What is the average speed for Abdul’s trip?

Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?

You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?

Why is the weight of an object on the moon 1/6th its weight on the earth?

A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.