① Pull-ups overcome their own gravity to do work, so weighing scale must be used to measure people's weight; To know the height of each mandibular elevation, you need to measure it with a scale; The time required for continuous completion of 16 pull-ups was measured with a stopwatch.

② From the power calculation formula P=Wt=Ght, we can see that the experimental steps are as follows: a) Weigh a person's weight g with a weight meter; B: Measure the rising height of the mandible with a scale; C: Measure the total time t of 16 times with a stopwatch.

③ The derivation process of power expression is: P=Wt= 16Ght.

So the answer is:

(1) weighing scale, scale, stopwatch

(2)A: Weigh a person's weight g with a weight meter;

B: measure the height h of human mandible with a scale,

C: Measure the total time t of 16 times with a stopwatch.

(3) Expression: P= 16Ght