Please Help! Which part of the technological design process involves learning from other scientists that have solved the problem before?

Also, this is a Science question.

Astone is dropped with no initial velocity from the top of a cliff and hits the ground a time of 3.9 s later. what is the height of the cliff, in units of meters? you may assume that air resistance is negligible. give the answer as a positive number question 15 a figure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 200 o 20.9 12000 o 3.33

Frequency of electromagnetic waves that a radio station is assigned. what do you call this type of wave?

Which of the following characteristics is fixed, or definite, for all states of matter?