CBSE Class 9   CBSE Class 9 Science


Give an application of density. What are its units? (1)
In the previous question, what will happen if instead of water the glass is filled with (1)
Calculate the work done against the gravity (1)
A piece of ice is placed gently on the surface of water in a glass so that when the ice floats, the water conies up to the brim of the glass (1)
What is the relationship between the commercial unit and SI unit of energy? (1)
The following figure shows' three identical blocks of wood floating in three different liquids A, B and C of densities d1,d2 and d3 respectively. Which of these has the highest density? Give reason to justify your answer (1)
What is the commercial unit of energy? (1)
Why does a camel walk easily on sand but it is difficult for a man to walk on sand though a camel is much heavier than a man? (1)
What kind of energy transformation takes place when a body is dropped from a certain height? (1)
State the laws of floatation (1)
Give one example each of potential energy (i) due to position (ii) due to shape (1)
A man squeezes a pin between his thumb and finger, as shown in figure (1)
Give any two uses of kinetic energy (1)
What is energy? What is unit of energy? (1)
During a period of hot weather, the atmospheric pressure on the pond shown in figure remains constant (1)
On what factors the work done on a body depends? (1)
Give two practical daily life applications that make use of the concept of pressure (1)
Give two examples from everyday life where work is done (1)
What do you mean by thrust? (1)
Figure shows a loudspeaker cone oscillating to produce sound waves: (1)
How does the weight of an object vary with respect to mass and radius of the earth? (1)
Show that the weight of an object on the moon is 1/6th of its weight on the earth (1)
Define acceleration due to gravity. Derive an expression for acceleration due to gravity in terms of mass of the earth (M) and universal gravitational constant (G) (1)
Derive expression for force of attraction between two bodies and then define gravitational constant (1)
Represent graphically any two separate diagrams in each case: (1)
Two objects of masses m1and m2 having the same size are dropped simultaneously from heights h1 and h2, respectively (1)
What is meant by reflection of sound? (1)
Prove that if a body is thrown vertically upward, the time of ascent is equal to the time of descent (1)
Give reasons for the following: The reverberation time of a hall used for speeches should be very short (1)
Calculate the average density of the earth in terms of g, G and R (1)