Matter in Our Surroundings — Science STD 9 — Question

Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.

What happens to the passengers travelling in a bus when the bus takes a sharp turn? Give reasons for your answer.

If a fresh egg is put into a beaker filled with water, it sinks. On dissolving a lot of salt in the water, the egg begins to rise and then floats. Why?

What would happen if plasma membrane ruptures?

What kind of energy transformations takes place at a coal-based thermal power station?

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.

Why is a liquid (the hydraulic fluid) used to operate the brakes in a car?

Define ‘molecular mass’ of a substance.

The time taken to stop a ball rolling with velocity u is reduced to half, find the change in values of:
Rate of momentum change.