English Medium कक्षा ९ - CBSE Question Bank Solutions for Science

Explain the following giving an example.

Colloid

Which of the following will show the “Tyndall effect”?

1. Salt solution
2. Milk
3. Copper sulphate solution
4. Starch solution

On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.

J.J. Thomson proposed that the nucleus of an atom contains only nucleons.

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

What is the nature of the distance-time graphs for uniform and non-uniform motion of an object?

What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?

A driver of a car travelling at 52 km h⁻¹ applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h⁻¹ in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?

Given figure shows the distance-time graph of three objects A, B and C. Study the graph and answer the following questions:

1. Which of the three is travelling the fastest?
2. Are all three ever at the same point on the road?
3. How far has C travelled when B passes A?
4. How far has B travelled by the time it passes C?

The speed-time graph for a car is shown in the following figure:

1. Find how far the car travels in the first 4 seconds. Shade the area on the graph that represents the distance travelled by the car during the period.
2. Which part of the graph represents uniform motion of the car?

When a carpet is beaten with a stick, dust comes out of it. Explain.

A batsman hits a cricket ball which then rolls on a level ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because ______.

What do you mean by buoyancy?

In what direction does the buoyant force on an object immersed in a liquid act?

Why are the ceilings of concert halls curved?

Why do organisms need water?

What is the major source of fresh water in the city/town/village where you live?

Why is water essential for life?

What does the slope of a distance-time graph indicate ?