WHY IS THIS SO

• Why do objects look different colours ?

The white light around us is made up of a mixture of different colours of light. The surfaces of objects absorb some colours and reflect others back. Our eye can see only those colours that are reflected. An object that reflects all the colours of light appears white and vice versa to this appears black. A tomato absorbs all the colours except red, which it reflects back to us. so that is how we are able to see tomato's red colour.

• Why do we need gravity?

Gravity is what keeps us and everything else, on earth. It is the tendency of objects with mass to be attracted to each other. an objects mass is the amount of material it contains. the bigger the mass of the object, the stronger will be it's gravity.

• Why can't we ever take a break from breathing?

Breathing takes air in and out of our lungs, and that air contains the gas oxygen. Every one of our trillion of body cells need a constant supply of oxygen, 24 hrs a day, and oxygen is something that our body cannot store- no break! Breathing also removes carbon dioxide from our body.