English Medium Class 9 - CBSE Question Bank Solutions for Science

A boy weighing 40 kg makes a high jump of 1.5 m.
What is his kinetic energy at the highest point?

A boy weighing 40 kg makes a high jump of 1.5 m.
What is his potential energy at the highest point? (g = 10 m/s²)

Give two examples where a body possesses both, kinetic energy as well as potential energy.

Define the term 'energy' of a body. What is the SI unit of energy.

What are the various forms of energy?

Two bodies having equal masses are moving with uniform speeds of v and 2v respectively. Find the ratio of their kinetic energies.

What is the difference between potential energy and kinetic energy?

A ball of mass 0.5 kg slows down from a speed of 5 m/s so that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.

An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass 3.5 kg. Both the spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same :

Water stored in a dam possesses ______.

A stone is thrown upwards as shown in the diagram. When it reaches P, which of the following has the greatest value of the stone?

How does the average temperature of Earth remain fairly steady?

Name the device or machine which convert :
Mechanical energy into electrical energy.

Name the device or machine which convert :
Chemical energy into electrical energy.

Name the device or machine which convert :
Electrical energy into heat energy.

Name the device or machine which convert :
Light energy into electrical energy.

Name the device or machine which convert :
Electrical energy into light energy.

Name the device or machine which convert :
Electrical energy into sound energy.

Name the device or machine which convert :
Heat energy into kinetic energy (or mechanical energy).