Can someone help me please

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Does the distance travelled by an oscillating mass between times t=0 and t2 equal the displacement of the particle over the same time period if t2> t/2? hint: consider a sine wave starting at t1=0, then consider a closing wave starting at t1=0, for your explanation.

X-ray crystallography is used to see the structure of molecules. scientists have used the technique to find the structure of cholesterol an important biological molecules knowledge of a structure of cholesterol is because it may affect?