Improvement in Food Resources — Science STD 9 — Question

If a potted plant is covered with a glass jar, water vapours appear on the wall of glass jar. Explain why?

What are simple tissres? Explain their three different types

Mention three effects of excessive irrigation

Where are the permanent tissues located in plant?

What are the advantages of composite fish culture?

Classify the following into true solutions and colloidal solutions: Ink, Salt solution, Starch solution, Blood, Sugar solution.

An artificial satellite is moving in a circular orbit of radius 42250km. Calculate its speed if it takes 24 hours to revolve around the earth.

A moving bicycle comes to rest after sometime if we stop pedalling it. But Newton’s first law of motion says that a moving body should continue to move for ever, unless some external force acts on it. How do you explain the bicycle case?

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term 'work'.

• Suma is swimming in a pond.
• A donkey is carrying a load on its back.
• A wind mill is lifting water from a well.
• A green plant is carrying out photosynthesis.
• An engine is pulling a train.
• Food grains are getting dried in the sun.
• A sailboat is moving due to wind energy.