Short answer type questions [3X3 = 9]
(i) Write three points on the usefulness of microorganisms in our life.
(ii) Explain the advantages of friction.
(iii) Write three differences between Thermoplastics and Thermosetting plastics.
PLEASE HELP ME PLEASE
Answers
Answer:
microorganism very useful for us
1) micro microorganism used to prepare vaccine for various disease.
2) they are useful for agriculture sector as they enchance the fertility of soil by fixing nitrogen
3) they work as natural cleaners, as they composed the dead bodies plant and animals
2) friction is responsible for type of motion it help us walk on the ground...... asteroid are burnt in the atmosphere before racing Earth due to friction . it help in the generating of heat when we rub your hands
difference between
3) these are some of the difference between thermoplastic and thermosetting plastic
thermoplastics - lower of molecular weight ,compared to two thermosetting plastics
thermosetting plastic- famous sorting plastic is high molecular weight