Natural Resources — Science STD 9 — Question

State the laws of reflection of sound.

'Milk is a very nutritious food'. Use the table given in the book to justify statement.

Do you agree that “A cell is a building unit of an organism”. If yes, explain why?

The velocity-time graph for part of a train journey is a horizontal straight line. What does this tell you about (a) the train’s velocity, and (b) about its acceleration?

What is apical meristem?

Draw a labeled diagram of the transverse section of this tissue.

Find the energy in joules consumed in 10 hours by four devices of power 500W each.

The power output of an engine is 3kW. How much work does the engine do in 20s?

Describe a method of separate a mixture of common salt and sand.

What is a stethoscope? Name the principle on which a stethoscope works.