Question

i) If $force=mass\times acceleration$, then $momentum=$ ________
ii) If liquid hydrogen is for rocket, then _______ is for MRI

Answer 1

1. If force = mass $\times$ acceleration, then momentum = mass $\times$ velocity
   
2. If liquid hydrogen is for rocket than liquid helium for MRI.
   

Helium is the preferred coolant to make the coils superconductive. It is colder than liquid Hydrogen