why did tom break myrtle's nose? how is this consistent with the author's description of him in chapter 1? judging by his treatment of myrtle and his wife daisy, what seems to be tom's attiude toward women?

Tom is abusive toward women;

But the quality of Tom that’s most likely to stick with you is the fact that he’s abusive. While we never see him get violent with his wife, there are hints of his unbridled physicality when Daisy reveals a bruise on her finger that, although accidental, was caused by Tom (or the "brute," as she calls him). Although he might not be physically abusive to his wife, Tom certainly causes her some emotional damage. There is, of course, his series of affairs, but he hurts Daisy in other ways, too. When Daisy tells us about her daughter being born, she casually adds that "Tom was God knows where." He is neither attentive nor sensitive towards his wife – especially in contrast to Gatsby. But, of course, Tom’s violent streak really comes across when we see him break Myrtle’s nose with the "short, deft movement" of his open hand. The curt language Fitzgerald uses here makes it clear that such violence means little to Tom. (1)

Tom broke Myrtles nose because he's angry at her continuous teasing that he's cheating on Daisy with her......she liked to throw it in his face.