Sound — Science STD 9 — Question

What can you say about the motion of a body if:

1. Its displacement-time graph is a straight line?
2. Its velocity-time graph is a straight line?

Name the complex tissue which helps in:

1. Conduction of water and minerals.
2. Conduction/ transport of food.

A car is moving on a level road. If the driver turns off the engine of the car, the car’s speed decreases gradually and ultimately it comes to a stop. A student says that two forces act on the car which bring it to a stop. What could these forces be? Which of these two forces contributes more to slow down and stop the car?

Why is it difficult to walk on a slippery road?

Define density. What is the SI unit of density?

A body floats in kerosene of density 0.8 × 10³ kg/m³ up to a certain mark. If the same body is placed in water of density 1.0 × 10³kg/m³, will it sink more or less? Give reason for your answer.

Why moon does not have an atmosphere?

What is green manuring? Give suitable example for green manures.

Calculate the momentum of a toy car of mass 200g moving with a speed of 5m/s.

How does roughage differ from concentrates with reference to cattle feed?