Motion — Science STD 9 — Question

A push or a pull:

__________ is the practice of growing a series of different types of crops in the same area in subsequent seasons:

A linear momentum of a body can be changed by:

Length of the straight line joining the initial to the final positions of a moving body is known as its:

A truck traveling due north at 50km/ hr turns west and travels at the same speed. What is the change in magnitude of speed:

Tallness and profuse branching are ideal for:

Evaporation is a _______ phenomenon.

Plant cells are rigid due to the presence of:

When a gas jar containing colourless air is kept upside down over a gas jar full of brown-coloured bromine vapour, then after sometime, the brown colour of bromine vapour spreads into the upper gas jar making both the gas jars appear brown in colour. Which of the following conclusion obtained from these observations is incorrect?

1. Bromine vapour is made of tiny particles which are moving.
2. Air is made up of tiny particles which are moving.
3. The particles of bromine are moving but those of air are not moving.
4. Even though bromine vapour is heavier than air, it can move up against gravity.

A rectangular wooden block has length, breadth and height of 50 cm, 25cm and 10cm, respectively. This wooden block is kept on ground in three different ways, turn by turn. Which of the following is the correct statement about the pressure exerted by this block on the ground?

1. The maximum pressure is exerted when the length and breadth form the base.
2. The maximum pressure is exerted when length and height form the base.
3. The maximum pressure is exerted when breadth and height form the base.
4. The minimum pressure is exerted when length and height form the base.