Whats the difference between relative dating and absolute dating

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

Each line (unit) on the horizontal axis represents: 5 years 10 years 20 years all of the above

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?