How do you know that waves sent from the sun to earth are not mechanical waves? Explain

Amachinist needs to remove a tight fitting pin of material a from a hole in a block made of material b. the machinist heats both the pin and the block to the same high temperature and removes the pin easily. what statement relates the coefficient of thermal expansion of material a to that of material b? a) the situation is not possible, heating block b will shrink the hole in the material as the material expands with increasing temperatureb) material b has the same coefficient of expansion as does material ac) material b has a negative coefficient of expansion and a has a positive coefficient of expansiond) material a has a greater coefficient of expansion than does material be) material b has a greate

Avector of magnitude 2 cannot be added to a vector of magnitude 3 so that the magnitude of the resultant is a. zero b. 1 c. 3 d. 5 e. 7

If anyonee has done the momentum lab practical in physics can you give me the answers i am s lostt rnn : (