physical factors are nothing but the abiotic factors which refers to land,air,water,sunlight etc. we can say that organisms on earth cannot survive without these factors.air which contains oxygen is very precious because oxygen is the breath of our is very necessary because without it life is not possible for us. water is very useful because it indirectly provides us food in the form of fishes etc. so life is not possible without these factors and hence they help for sustenance of the habitat.
Physical Factors are simply the things that provide us with our needs indirectly. For example, air is giving us oxygen to breathe. We are not breathing in the air. We are breathing in the oxygen in the air. And then water is providing us with water and food. We are not drinking up the water from seas or oceans diretly. We are purifying it and then consuming it. And the sea creatures in the water are eaten as serafood by non vegetarians. So physical factors are providing us with our daily needs and wants indirectly.
Hope I Helped...