Sound — Science STD 9 — Question

Which of the following are the closest pets of human beings?

Two chemical species X and Y combine together to form a product P which contains both X and Y, X + Y → P X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?

1. P is a compound.
2. X and Y are compounds.
3. X and Y are elements.
4. P has a fixed composition.

Infrasound can be heard by:

Paddy and soya beans are:

When slinky is stretched out in a horizontal direction and first coils are vibrated horizontally then which waves are generated?

When both crops and livestock are raised on the same farm, it is known as:

An organism made up of many cells is known as:

The numerical ratio of displacement to distance for a moving object is:

The speeds of sound in four different media are given below. Which of the following is the most likely speed in m/s with which the two under water whales in a sea talk to each other when separated by a large distance?

1. 340
2. 5170
3. 1280
4. 1530

The theory of Democritus state that: