Hi all, could you solve this please?
What is the value of the resistance R

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Apure substance is a)-mixture of various chemical elements or compounds b)-substance that has a fixed chemical composition throughout c)-mixture that is homogeneous (such as air) d)-all the answers