Gravitation — Science STD 9 — Question

Define momentum of a body. On what factors does the momentum of a body depend?

Explain why, it is dangerous to jump out of a moving bus.

A body of mass 5kg is moving with a velocity of 10m/s. A force is applied to it so that in 25 seconds, it attains a velocity of 35m/s. Calculate the value of the force applied.

Potassium chlorate decomposes, on heating, to form potassium chloride and oxygen. When 24.5g of potassium chlorate is decomposed completely, then 14.9g of potassium chloride is formed. Calculate the mass of oxygen formed. Which law of chemical combination have you used in solving this problem?

An ant travels a distance of 8cm from P to Q and then moves a distance of 6cm at right angles to PQ. Find its resultant displacement.

When a gas jar containing air is inverted over a gas jar containing bromine vapour, the red-brown bromine vapour diffuse into air. Explain how bromine vapour diffuse into air.

State Newton’s first law of motion. Give two examples to illustrate Newton’s first law of motion.

Explain why, we can easily move our hand in air but to do the same through a plank of wood, we need a karate expert.

Define the term ‘uniform acceleration’. Give one example of a uniformly accelerated motion.