The surge in luteinizing hormone that occurs during the middle of the ovarian cycle triggers

Ovulation  

Explanation:

In women, luteinizing hormone carries out different roles in the two halves of the menstrual cycle

In week one to two of the cycle, luteinizing hormone is required to stimulate the ovarian follicles in the ovary to produce the female sex hormone, oestradiol Around day 14 of the cycle, a surge in  luteinizing hormone levels causes the ovarian follicle to tear and release a mature oocyte (egg) from the ovary, a process called ovulationFor the remainder of the cycle (weeks three to four), the remnants of the ovarian follicle forms a corpus luteumLuteinizing hormone stimulates the corpus luteum to produce progesterone, which is required to support the early stages of pregnancy, if fertilization occurs

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on