Apair of scissors is a complex machine. what are the simple machines you need, to make a pair of scissors?

Suppose that a comet that was seen in 563 a.d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Iwill give 30 points to whoever answers ! what is the formula for actual mechanical advantage and ideal mechanical advantage?